FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2022762164> ?p ?o ?g. }

• W2022762164 endingPage "1846" @default.
• W2022762164 startingPage "1843" @default.
• W2022762164 abstract "JIP-1 is a cytoplasmic inhibitor of the c-Jun amino-terminal kinase activated pathway recently cloned from a mouse brain cDNA library. We report herein the expression cloning of a rat cDNA encoding a JIP-1-related nuclear protein from a pancreatic β-cell cDNA library that we named IB1 for Islet-Brain 1. IB1 was isolated by its ability to bind to GTII, a cis-regulatory element of the GLUT2 promoter. The IB1 cDNA encodes a 714-amino acid protein, which differs from JIP-1 by the insertion of 47 amino acids in the carboxyl-terminal part of the protein. The remaining 667 amino acids are 97% identical to JIP-1. The 47-amino acid insertion contains a truncated phosphotyrosine interaction domain and a putative helix-loop-helix motif. Recombinant IB1 (amino acids 1–714 and 280–714) was shown to bind in vitro to GTII. Functionally IB1 transactivated the GLUT2 gene. IB1 was localized within the cytoplasm and the nucleus of insulin-secreting cells or COS-7 cells transfected with an expression vector encoding IB1. Using a heterologous GAL4 system, we localized an activation domain of IB1 within the first 280 amino acids of the protein. These data demonstrate that IB1 is a DNA-binding protein related to JIP-1, which is highly expressed in pancreatic β-cells where it functions as a transactivator of the GLUT2 gene. JIP-1 is a cytoplasmic inhibitor of the c-Jun amino-terminal kinase activated pathway recently cloned from a mouse brain cDNA library. We report herein the expression cloning of a rat cDNA encoding a JIP-1-related nuclear protein from a pancreatic β-cell cDNA library that we named IB1 for Islet-Brain 1. IB1 was isolated by its ability to bind to GTII, a cis-regulatory element of the GLUT2 promoter. The IB1 cDNA encodes a 714-amino acid protein, which differs from JIP-1 by the insertion of 47 amino acids in the carboxyl-terminal part of the protein. The remaining 667 amino acids are 97% identical to JIP-1. The 47-amino acid insertion contains a truncated phosphotyrosine interaction domain and a putative helix-loop-helix motif. Recombinant IB1 (amino acids 1–714 and 280–714) was shown to bind in vitro to GTII. Functionally IB1 transactivated the GLUT2 gene. IB1 was localized within the cytoplasm and the nucleus of insulin-secreting cells or COS-7 cells transfected with an expression vector encoding IB1. Using a heterologous GAL4 system, we localized an activation domain of IB1 within the first 280 amino acids of the protein. These data demonstrate that IB1 is a DNA-binding protein related to JIP-1, which is highly expressed in pancreatic β-cells where it functions as a transactivator of the GLUT2 gene. In an attempt to identify DNA-binding proteins necessary for proper β-cell-specific expression of genes in the endocrine pancreas, we initiated the characterization of the promoter of the GLUT2 gene. GLUT2, a facilitated glucose transporter isoform, is a membrane protein present in pancreatic β-insulin-secreting cells, the basolateral membrane of intestinal and kidney absorptive cells, in hepatocytes, and in a subset of neurons (1Thorens B. Sarkar H.K. Kaback H.R. Lodish H.F. Cell. 1988; 55: 281-290Abstract Full Text PDF PubMed Scopus (661) Google Scholar, 2Leloup C. Arluison M. Lepetit N. Cartier N. Marfaing-Jallat P. Ferré P. Pénicaud L. Brain Res. 1994; 638: 221-226Crossref PubMed Scopus (182) Google Scholar, 3Orci L. Thorens B. Ravazzola M. Lodish H.F. Science. 1989; 245: 295-297Crossref PubMed Scopus (170) Google Scholar). In several experimental models of diabetes, GLUT2 expression is dramatically reduced in pancreatic β-cells, and it has been suggested a role for GLUT2 in the pathogenesis of the disease (4Johnson J.H. Ogawa A. Chen L. Orci L. Newgard C.B. Alam T. Unger R.H. Science. 1990; 250: 546-548Crossref PubMed Scopus (180) Google Scholar, 5Ohneda M. Johnson J.H. Inman L.R. Chen L. Suzuki K.I. Goto Y. Alam T. Ravazzola M. Orci L. Unger R.H. Diabetes. 1993; 42: 1065-1072Crossref PubMed Scopus (79) Google Scholar, 6Orci L. Unger R.H. Ravazzola M. Ogawa A. Komiyia I. Baetens D. Lodish H.F. Thorens B. J. Clin. Invest. 1990; 86: 1615-1622Crossref PubMed Scopus (80) Google Scholar, 7Orci L. Ravazzola M. Baetens D. Inman L. Amherdt M. Peterson R.G. Newgard C.B. Johnson J.H. Unger R.H. Proc. Natl. Acad. Sci. U. S. A. 1990; 87: 9953-9957Crossref PubMed Scopus (126) Google Scholar, 8Thorens B. Wu Y.-J. Leahy J.L. Weir G.C. J. Clin. Invest. 1992; 90: 77-85Crossref PubMed Scopus (142) Google Scholar, 9Thorens B. Weir G.C. Leahy J.L. Lodish H.F. Bonner-Weir S. Proc. Natl. Acad. Sci. U. S. A. 1990; 87: 6492-6496Crossref PubMed Scopus (137) Google Scholar, 10Unger R.H. Science. 1991; 251: 1200-1205Crossref PubMed Scopus (253) Google Scholar). We and others have shown that a fragment of the GLUT2 promoter displayed glucose responsiveness when transfected into differentiated insulin-producing cells or into hepatocytes (11Waeber G. Thompson N. Haefliger J.-A. Nicod P. J. Biol. Chem. 1994; 269: 26912-26919Abstract Full Text PDF PubMed Google Scholar, 12Rencurel F. Waeber G. Antoine B. Rocchiccioli F. Maulard P. Girard J. Biochem. J. 1996; 314: 903-909Crossref PubMed Scopus (95) Google Scholar, 13Rencurel F. Waeber G. Bonny C. Antoine B. Maulard P. Girard J. Leturque A. Biochem. J. 1997; 322: 441-448Crossref PubMed Scopus (12) Google Scholar). Important cis-regulatory sequences were identified within this promoter region, including functionally responsive PDX-1 and cyclic AMP-responsive elements and threecis sequences named GTI, GTII, and GTIII (13Rencurel F. Waeber G. Bonny C. Antoine B. Maulard P. Girard J. Leturque A. Biochem. J. 1997; 322: 441-448Crossref PubMed Scopus (12) Google Scholar, 14Bonny C. Thompson N. Nicod P. Waeber G. Mol. Endocrinol. 1995; 9: 1413-1426PubMed Google Scholar, 15Waeber G. Thompson N. Nicod P. Bonny C. Mol. Endocrinol. 1996; 10: 1327-1334Crossref PubMed Scopus (325) Google Scholar). The minimal promoter region containing GTI, GTII, and GTIII is both sufficient and necessary to confer pancreatic expression to a reporter gene in vitro or in vivo in transgenic mice (14Bonny C. Thompson N. Nicod P. Waeber G. Mol. Endocrinol. 1995; 9: 1413-1426PubMed Google Scholar,16Waeber G. Pedrazzini T. Bonny O. Bonny C. Steinmann M. Nicod P. Haefliger J.-A. Mol. Cell. Endocrinol. 1995; 114: 205-215Crossref PubMed Scopus (20) Google Scholar). Nuclear proteins specifically expressed in pancreatic β-cells interact with the GTII sequence (14Bonny C. Thompson N. Nicod P. Waeber G. Mol. Endocrinol. 1995; 9: 1413-1426PubMed Google Scholar). In this report, we describe the expression cloning of a GTII-binding protein from a pancreatic β-cell cDNA library. The gene encodes a cDNA abundantly expressed in the pancreatic islets and in the brain, which was named IB-1 for Islet-Brain 1 (17.Bonny, C., Nicod, P., and Waeber, G. (1997) International Endocrine Society Meeting, June 11–14, 1997, Minneapolis, MN, Abstract OR36–3-117.Google Scholar). A GeneBank™ data base search with the IB1 cDNA revealed that IB1 is a rat homologue of the murine cytoplasmic inhibitor of the c-Jun amino-terminal kinase (JNK) 1The abbreviations used are: JNK, c-Jun amino-terminal kinase; PID, phosphotyrosine interaction domain; HLH, helix-loop-helix motif; CMV, cytomegalovirus; bp, base pair(s); aa, amino acids.-activated pathway termed JIP-1 (18Dickens M. Rogers J.S. Cavanagh J. Raitano A. Xia Z. Halpern J.R. Greenberg M.E. Sawyers C.L. Davis R.J. Science. 1997; 277: 693-696Crossref PubMed Scopus (628) Google Scholar). IB1 differs, however, from JIP-1 by the insertion of a 47-amino acid region in its carboxyl-terminal part. This insertion encodes a phosphotyrosine interactiondomain (PID) and a helix-loop-helix motif (HLH). Furthermore, IB1 is a cytoplasmic and nuclear DNA-binding protein, which functions as transactivator of the GLUT2 gene. An oligo(dT)-primed cDNA was generated from 10 μg of poly(A)+ RNA obtained from the differentiated INS-1 insulin-secreting cell line using a cDNA synthesis kit (Stratagene, La Jolla, CA) according to the manufacturer's instructions. The cDNAs were cloned into theEcoRI and XhoI sites of the λZap Express expression vector (Stratagene). A total of 2 × 106colonies were screened by the procedure described by Singh et al. (19Singh H. LeBowitz J.H. Baldwin A.S. Sharp P.A. Cell. 1988; 52: 415-423Abstract Full Text PDF PubMed Scopus (419) Google Scholar) using as probe concatanated GTII oligonucleotides (14Bonny C. Thompson N. Nicod P. Waeber G. Mol. Endocrinol. 1995; 9: 1413-1426PubMed Google Scholar). One GTII-interacting positive clone was obtained from the screening and excised. The resulting cDNA in the pBKS plasmid (pBKS-IB1) was sequenced in both 5′ and 3′ orientations. The transplantable x-ray induced rat insulinoma INS-1 cell line was kindly provided by Asfari et al. (20Asfari M. Janjic D. Meda P. Li G. Halban P.A. Wollheim C.B. Endocrinology. 1992; 130: 167-178Crossref PubMed Scopus (748) Google Scholar) and grown as described. The mouse insulin-producing βTC3 cell line and the kidney-derived COS-7 cell line were cultured as described previously (21Efrat S. Linde S. Kofod H. Spector D. Delannoy M. Grant S. Hanahan D. Baekkeskov S. Proc. Natl. Acad. Sci. U. S. A. 1988; 85: 9037-9041Crossref PubMed Scopus (473) Google Scholar, 22Takaki R. Ono J. Nakamura M. Yokogawa Y. Kumae S. Hiraoka T. Yamaguchi K. Hamaguchi K. Uchida S. In Vitro Cell & Dev. Biol. 1986; 22: 120-126Crossref PubMed Scopus (82) Google Scholar). The eukaryotic expression vector encoding IB1 was constructed by inserting the IB1 cDNA in the NheI/XhoI sites of the CMV-driven plasmid PBKS (Stratagene) to generate the pCMV-IB1 vector. Polymerase chain reaction mutagenesis was used to add a Flag epitope (Eastman Kodak Co.) in the pCMV-IB1 construct 3′ of the initiating methionine. The −338 bp of the murine GLUT2 promoter (14Bonny C. Thompson N. Nicod P. Waeber G. Mol. Endocrinol. 1995; 9: 1413-1426PubMed Google Scholar) were cloned 5′ of a luciferase gene (pGL3Basic vector, Promega, Madison, WI). For the GAL4 constructs, the IB1 cDNA was introduced into the pSG147 vector, in frame with the GAL4 DNA-binding domain (aa 1–147) of this vector (23Sadowski I. Ptashne M. Nucleic Acids Res. 1989; 17: 7539Crossref PubMed Scopus (471) Google Scholar). The luciferase reporter construct used in the GAL4 system was obtained by linking five copies of the GAL4 DNA-binding sites (5 × GAL4 DNA-binding sites) 5′ to the minimal herpes simplex virus thymidine kinase promoter in the pGL3-TK plasmid (Promega). All constructs were transiently transfected using the cationic reagent DOTAP (Boehringer Mannheim, Mannheim, Germany) as described previously (14Bonny C. Thompson N. Nicod P. Waeber G. Mol. Endocrinol. 1995; 9: 1413-1426PubMed Google Scholar). Luciferase activities were measured according to the protocol of Brasier et al. (24Brasier A.R. Tate J.E. Habener J.F. BioTechniques. 1989; 7: 1116-1121PubMed Google Scholar). Nuclear and cytoplasmic extracts were prepared according to the method of Dent and Latchmann (25Dent C.L. Latchman D.S. Latchman D.S. Transcription Factors: A Practical Approach. Oxford University Press, New York1993: 1-26Google Scholar). The SouthWestern experiments were conducted as described (14Bonny C. Thompson N. Nicod P. Waeber G. Mol. Endocrinol. 1995; 9: 1413-1426PubMed Google Scholar). The in vitro translation experiments were performed from the pBKS-IB1 plasmid as template using the coupled transcription-translation kit (TNT) from Promega and according to the manufacturer's instructions in the presence of [35S]methionine. The RNA isolation and Northern blot analysis from rat tissues or cell lines were conducted exactly as described previously (14Bonny C. Thompson N. Nicod P. Waeber G. Mol. Endocrinol. 1995; 9: 1413-1426PubMed Google Scholar). The rat pancreatic islets were isolated by the method of Gotoh et al. (26Gotoh M. Maki T. Satomi T. Porter J. Bonner-Weir S. O'Hara C.J. Monaco A.P. Transplantation. 1987; 43: 725-730Crossref PubMed Scopus (209) Google Scholar). Anti-IB1 antiserum was prepared using a cDNA fragment encoding the first 280 amino acids of the protein. This fragment was inserted into the His-tagged pQE-9 expression vector (Qiagen, Basel, Switzerland), expressed, and purified through a Ni2+-containing column following instructions from the manufacturer. Purified material was used to elicit polyclonal antibodies in rabbits. To affinity-purify the antibodies, the Ni2+-column-purified 1–280 aa of the recombinant protein were immobilized onto a nitrocellulose membrane, and the rabbit antiserum (diluted 1:50 in phosphate-buffered saline) was incubated with this membrane. The membrane was then washed in phosphate-buffered saline buffer, and the anti-IB1 antibody was eluted by 0.2m Tris-glycine, pH 2.8, followed by neutralization at pH ∼7.5. The preimmune serum was treated in a similar fashion to provide non-immune control. The immunocytochemistry was performed essentially as described previously (16Waeber G. Pedrazzini T. Bonny O. Bonny C. Steinmann M. Nicod P. Haefliger J.-A. Mol. Cell. Endocrinol. 1995; 114: 205-215Crossref PubMed Scopus (20) Google Scholar). The sections were incubated for 14 h at 4 °C with the affinity-purified preimmune or immune anti-IB1 serum (dilution 1/200). A DNA binding activity to GTII was shown to be restricted to insulin-secreting cells (INS-1 and βTC3) (14Bonny C. Thompson N. Nicod P. Waeber G. Mol. Endocrinol. 1995; 9: 1413-1426PubMed Google Scholar). A poly(dT)-primed INS-1 cDNA expression library was constructed and screened by the procedure described by Singh et al. (19Singh H. LeBowitz J.H. Baldwin A.S. Sharp P.A. Cell. 1988; 52: 415-423Abstract Full Text PDF PubMed Scopus (419) Google Scholar) using a concatanated GTII oligonucleotide probe. One positive clone was isolated from a primary screen of approximately 2 × 106 phage plaques. The 2,953-bp-long insert encoded a large open reading frame of 714 amino acids and was termed IB1, for Islet-Brain 1, as its expression was primarily restricted to these two tissues, as discussed below (17.Bonny, C., Nicod, P., and Waeber, G. (1997) International Endocrine Society Meeting, June 11–14, 1997, Minneapolis, MN, Abstract OR36–3-117.Google Scholar). A GeneBank™ data base search revealed that IB1 is a rat homologue of the recently identified JIP-1 protein (18Dickens M. Rogers J.S. Cavanagh J. Raitano A. Xia Z. Halpern J.R. Greenberg M.E. Sawyers C.L. Davis R.J. Science. 1997; 277: 693-696Crossref PubMed Scopus (628) Google Scholar). JIP-1 is a cytoplasmic inhibitor of the JNK-activated pathway, which was cloned from a mouse brain cDNA library using a two-hybrid system (18Dickens M. Rogers J.S. Cavanagh J. Raitano A. Xia Z. Halpern J.R. Greenberg M.E. Sawyers C.L. Davis R.J. Science. 1997; 277: 693-696Crossref PubMed Scopus (628) Google Scholar). Amino acid and nucleic acid comparison of mouse JIP-1 and rat IB1 showed that the proteins are almost identical (97% identity) with the exception of a 47-amino acid addition in the carboxyl-terminal part of IB1. As depicted in Fig.1, this 47-amino acid insertion contains a putative helix-loop-helix domain as well as a PID. PID domains are an average length of 100–160 amino acids and consist of four conserved blocks (27Bork P. Margolis B. Cell. 1995; 80: 693-694Abstract Full Text PDF PubMed Scopus (172) Google Scholar, 28Harrison S.C. Cell. 1996; 86: 341-343Abstract Full Text Full Text PDF PubMed Scopus (153) Google Scholar). The first block of the putative PID domain of IB1 is contained in the 47-amino acid insertion and therefore is absent from the JIP-1 protein. JIP-1 was shown to be a cytoplasmic protein that caused cytoplasmic retention of JNK and that inhibited the JNK-regulated gene expression (18Dickens M. Rogers J.S. Cavanagh J. Raitano A. Xia Z. Halpern J.R. Greenberg M.E. Sawyers C.L. Davis R.J. Science. 1997; 277: 693-696Crossref PubMed Scopus (628) Google Scholar). As JNK binds in the nuclei to the transcription factors c-Jun and ATF2, the sequestration of JNK by JIP-1 in the cytoplasm inhibits the JNK signaling pathway. One may speculate that the insertion of the 47 amino acids in the JIP-1 protein, which creates a HLH and a PID domain, will allow protein-protein interactions, possibly with other members of the tyrosine kinase signaling pathway or with transcription factors. By computer analysis using the SOPMA algorithm (Self Optimized Prediction Method of Alignments, CNRS, Lyon, France), two acidic helicoidal structures (aa 31–61 and 114–125) and a proline-rich region (aa 292–366) in the amino-terminal part of IB1 were also predicted, which could act as transactivation domains (29Mitchell P.J. Tjian R. Science. 1989; 245: 371-378Crossref PubMed Scopus (2206) Google Scholar). Putative nuclear localization signals were also localized at aa 163–190 and 242–270 (30Dingwall C. Laskey R.A. Trends Biochem. Sci. 1991; 16: 478-481Abstract Full Text PDF PubMed Scopus (1711) Google Scholar). IB1, as JIP-1, was highly expressed in the brain and, to a lower extent, in the kidney (17.Bonny, C., Nicod, P., and Waeber, G. (1997) International Endocrine Society Meeting, June 11–14, 1997, Minneapolis, MN, Abstract OR36–3-117.Google Scholar, 18Dickens M. Rogers J.S. Cavanagh J. Raitano A. Xia Z. Halpern J.R. Greenberg M.E. Sawyers C.L. Davis R.J. Science. 1997; 277: 693-696Crossref PubMed Scopus (628) Google Scholar). In addition, IB1 was also abundantly expressed in several insulin-secreting cell lines (INS-1, RIN5F) as well as in freshly isolated rat pancreatic islets, but not in the liver or in RNA prepared from whole pancreas, since the pancreatic islets represent a small proportion of the organ (Fig. 2,A and B). In pancreatic islets, IB1 expression was not regulated by increasing the glucose concentration in the incubation medium from 2.8 to 30 mm (Fig. 2 B). Affinity-purified antibodies detected a 120-kDa protein in nuclear extracts prepared from βTC3 cells and in crude cellular extracts prepared from freshly isolated pancreatic islets (Fig. 2, Cand D). This 120-kDa protein comigrated with the product obtained by in vitro transcription-translation of the IB1 cDNA in the presence of [35S]methionine (data not shown). We could also detect the IB1 protein in both nuclear and cytoplasmic extracts obtained from COS-7 cells transiently transfected with the CMV-driven IB1 cDNA (Fig. 2 E). To gain further insight into the tissue and cellular localization of IB1 within the pancreas, immunohistochemistry studies were performed on mouse islets and βTC3 cells. Affinity-purified antibodies raised against IB1 detected this factor in the pancreatic islet as well as in the nuclei and the cytoplasm of βTC3 cells (Fig.3, A and C). To confirm the specificity of the anti-IB1 antibodies in immunocytochemistry, a construct was generated that includes a Flag epitope located NH2-terminal to the IB1 protein expressed under the control of a CMV promoter. This construct was transiently transfected into COS-7 cells, and the translated product was immunodetected with an anti-Flag antibody subsequently visualized by fluorescein isothiocyanate staining (Fig. 3 E) or with the anti-IB1 antibody detected using an anti-rabbit Texas Red-labeled antibody (Fig. 3 F). The IB1 protein, in transfected COS-7 cells, was detected with both the anti-Flag and the anti-IB1 antibodies in the cytoplasm and the nuclei of COS-7 cells. The IB1 cDNA was cloned 3′ to a CMV promoter and transiently transfected into COS-7, a cell line that does not express endogenous IB1. Crude cellular extracts prepared from these transfected cells were then analyzed by the SouthWestern technique using the GTII probe. A 120-kDa GTII-binding protein was detected by SouthWestern (Fig. 4), and this size product was similar to the one obtained by in vitro translation of the IB1 cDNA in the presence of [35S]methionine and to the protein detected by anti-IB1 antibodies (Fig. 2). The IB1 cDNA is therefore translated into a 120-kDa product, which is able to bind the GTII probe. Constructs were then generated that include only the amino-terminal part (aa 1–280) or the COOH-terminal part (280–714) of the protein, and bacterially produced recombinant IB1 proteins were obtained from these plasmids. The 280–714-aa protein, but not the 1–280-aa protein, was able to bind to the GTII cis sequence when tested by SouthWestern analysis implying that the carboxyl end of the protein contains the DNA-binding domain of IB1 (data not shown). Transcriptional activation by IB1 was assessed by cotransfection experiments in the insulin-secreting cell line βTC3, an IB1 expression vector (pCMV-IB1), and the proximal region of the GLUT2 promoter (−338 bp) linked to a luciferase reporter gene. Overexpression of IB1 transactivated the GLUT2 promoter 1.6 (±0.1)-fold when compared with a cotransfection with the expression vector lacking the IB1 cDNA (PBKS). This effect was absent with the promoterless reporter construct (pGL3). To avoid possible interference with endogenous IB1 protein interacting with GTII and/or heterodimerization of IB1 with related factors, aa 1–268 and 1–714 of IB1 were fused with the GAL4 DNA-binding domain. The GTII-binding sites of the reporter gene were replaced with GAL4-binding sites linked to a minimal thymidine kinase-luciferase gene. As shown in Fig.5, the amino-terminal part of IB1 was sufficient to confer transactivating functions to this heterologous GAL4 system (9.0 ± 0.4 and 7.5 ± 1.2 versuscontrol with the 1–268 and 1–714 GAL4 constructs, respectively). In summary, we describe herein the expression cloning, using acis-regulatory element of the GLUT2 promoter, of a protein preferentially expressed in the brain and the insulin-secreting cells named IB1 (17.Bonny, C., Nicod, P., and Waeber, G. (1997) International Endocrine Society Meeting, June 11–14, 1997, Minneapolis, MN, Abstract OR36–3-117.Google Scholar). The rat IB1 amino acid sequence is 97% identical to the recently described murine JIP-1 cytoplasmic protein (18Dickens M. Rogers J.S. Cavanagh J. Raitano A. Xia Z. Halpern J.R. Greenberg M.E. Sawyers C.L. Davis R.J. Science. 1997; 277: 693-696Crossref PubMed Scopus (628) Google Scholar). JIP-1 and IB1 differ mainly by the presence of a 47-amino acid insertion in the carboxyl-terminal part of IB1, which complements a truncated HLH and PID domain (27Bork P. Margolis B. Cell. 1995; 80: 693-694Abstract Full Text PDF PubMed Scopus (172) Google Scholar, 28Harrison S.C. Cell. 1996; 86: 341-343Abstract Full Text Full Text PDF PubMed Scopus (153) Google Scholar). JIP-1 was cloned by its ability to bind to JNK, implying the existence of protein-protein interactions, while IB1 was isolated by its ability to bind to a cis-regulatory element of the GLUT2 promoter, implying DNA-protein interactions. This DNA binding activity was not suspected for JIP-1, and several lines of evidence suggest that indeed IB1 is a DNA-binding protein and acts as a transcriptional factor. First, IB1 was cloned based on its ability to bind to the GTII cis element. Second, the SouthWestern experiments could detect IB1 in nuclear extracts of transfected COS-7 cells with the expression vector encoding IB1. Third, immunodetectable nuclear staining was present in pancreatic islets as well as in βTC3 cells. Fourth, Western blot analysis of these cells could also detect IB1 in the cytoplasm and in the nucleus. Further work will be needed to identify other potential partners of the IB1/JIP-1 proteins, either other transcriptional factors or other members of the JNK signaling pathway. It remains to be elucidated whether IB1/JIP-1 plays a differential functional role in the insulin-secreting cells, in particular in the control of glucose-induced insulin secretion. We are grateful to Myriam Steinmann for excellent technical assistance and to Vincent Mooser, Phil Shaw, Bernard Thorens and Nancy Thompson for critical comments." @default.
• W2022762164 created "2016-06-24" @default.
• W2022762164 creator A5002023781 @default.
• W2022762164 creator A5047797878 @default.
• W2022762164 creator A5050307056 @default.
• W2022762164 date "1998-01-01" @default.
• W2022762164 modified "2023-10-15" @default.
• W2022762164 title "IB1, a JIP-1-related Nuclear Protein Present in Insulin-secreting Cells" @default.
• W2022762164 cites W1530092824 @default.
• W2022762164 cites W1645877609 @default.
• W2022762164 cites W1973163317 @default.
• W2022762164 cites W197438496 @default.
• W2022762164 cites W1983260994 @default.
• W2022762164 cites W1986758681 @default.
• W2022762164 cites W1987390815 @default.
• W2022762164 cites W1988178015 @default.
• W2022762164 cites W1989297216 @default.
• W2022762164 cites W1997859241 @default.
• W2022762164 cites W2000977514 @default.
• W2022762164 cites W2001130216 @default.
• W2022762164 cites W2002390599 @default.
• W2022762164 cites W2011509827 @default.
• W2022762164 cites W2032889432 @default.
• W2022762164 cites W2036735866 @default.
• W2022762164 cites W2038862314 @default.
• W2022762164 cites W2047604959 @default.
• W2022762164 cites W2050809104 @default.
• W2022762164 cites W2054777152 @default.
• W2022762164 cites W2063720970 @default.
• W2022762164 cites W2068577315 @default.
• W2022762164 cites W2069116251 @default.
• W2022762164 cites W2073962811 @default.
• W2022762164 cites W2074045232 @default.
• W2022762164 cites W2075496313 @default.
• W2022762164 cites W2075542857 @default.
• W2022762164 cites W2078709292 @default.
• W2022762164 cites W2082670705 @default.
• W2022762164 cites W2086725260 @default.
• W2022762164 cites W2102328371 @default.
• W2022762164 cites W2120982408 @default.
• W2022762164 cites W2150295206 @default.
• W2022762164 cites W2170588602 @default.
• W2022762164 doi "https://doi.org/10.1074/jbc.273.4.1843" @default.
• W2022762164 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/9442013" @default.
• W2022762164 hasPublicationYear "1998" @default.
• W2022762164 type Work @default.
• W2022762164 sameAs 2022762164 @default.
• W2022762164 citedByCount "138" @default.
• W2022762164 countsByYear W20227621642012 @default.
• W2022762164 countsByYear W20227621642013 @default.
• W2022762164 countsByYear W20227621642014 @default.
• W2022762164 countsByYear W20227621642015 @default.
• W2022762164 countsByYear W20227621642016 @default.
• W2022762164 countsByYear W20227621642017 @default.
• W2022762164 countsByYear W20227621642019 @default.
• W2022762164 countsByYear W20227621642020 @default.
• W2022762164 countsByYear W20227621642021 @default.
• W2022762164 countsByYear W20227621642023 @default.
• W2022762164 crossrefType "journal-article" @default.
• W2022762164 hasAuthorship W2022762164A5002023781 @default.
• W2022762164 hasAuthorship W2022762164A5047797878 @default.
• W2022762164 hasAuthorship W2022762164A5050307056 @default.
• W2022762164 hasBestOaLocation W20227621641 @default.
• W2022762164 hasConcept C126322002 @default.
• W2022762164 hasConcept C134018914 @default.
• W2022762164 hasConcept C185592680 @default.
• W2022762164 hasConcept C2779306644 @default.
• W2022762164 hasConcept C71924100 @default.
• W2022762164 hasConcept C86803240 @default.
• W2022762164 hasConceptScore W2022762164C126322002 @default.
• W2022762164 hasConceptScore W2022762164C134018914 @default.
• W2022762164 hasConceptScore W2022762164C185592680 @default.
• W2022762164 hasConceptScore W2022762164C2779306644 @default.
• W2022762164 hasConceptScore W2022762164C71924100 @default.
• W2022762164 hasConceptScore W2022762164C86803240 @default.
• W2022762164 hasIssue "4" @default.
• W2022762164 hasLocation W20227621641 @default.
• W2022762164 hasOpenAccess W2022762164 @default.
• W2022762164 hasPrimaryLocation W20227621641 @default.
• W2022762164 hasRelatedWork W1966504330 @default.
• W2022762164 hasRelatedWork W1966775726 @default.
• W2022762164 hasRelatedWork W1979139803 @default.
• W2022762164 hasRelatedWork W1991560548 @default.
• W2022762164 hasRelatedWork W2030889776 @default.
• W2022762164 hasRelatedWork W2037631372 @default.
• W2022762164 hasRelatedWork W2040058909 @default.
• W2022762164 hasRelatedWork W2132898409 @default.
• W2022762164 hasRelatedWork W2748952813 @default.
• W2022762164 hasRelatedWork W4249176446 @default.
• W2022762164 hasVolume "273" @default.
• W2022762164 isParatext "false" @default.
• W2022762164 isRetracted "false" @default.
• W2022762164 magId "2022762164" @default.
• W2022762164 workType "article" @default.