Matches in SemOpenAlex for { <https://semopenalex.org/work/W2160188581> ?p ?o ?g. }
Showing items 1 to 79 of
79
with 100 items per page.
- W2160188581 endingPage "e1003745" @default.
- W2160188581 startingPage "e1003745" @default.
- W2160188581 abstract "Perspective Past Visits Present: TCF/LEFs Partner with ATFs for b- Catenin–Independent Activity Stephanie Sprowl, Marian L. Waterman* Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, California, United States of America TCF/LEF transcription factors are best known for their role as mediators of Wnt signaling, helping Wnt direct devel- opmental transitions of stem cells in tissues or driving cell transformation and cancer when Wnt is aberrantly active. These factors possess a High Mobility Group DNA-binding domain that recognizes a motif called the Wnt Response Element (WRE: 59-CTTTGWW-39) and an N- terminal domain that binds b-catenin (Figure 1A). b-catenin is the cytoplasmic- nuclear mediator that communicates Wnt signals from the plasma membrane to TCF/LEFs for transcription activation (Figure 1C). The vast majority of pub- lished studies about TCF/LEFs focus on their recruitment of this mediator to Wnt target genes. This implies that ‘‘life’’ for TCF/LEFs began in 1996 when yeast two hybrid screens identified their mutual, strong interaction [1–3]. In fact, discovery of TCF/LEFs had nothing to do with Wnt and b-catenin. TCF/LEFs were first described as DNA-binding proteins that regulated transcription of lymphocyte- specific genes such as the T-Cell Receptor complex, and they did so by cooperating with transcription factors bound to juxta- posed elements in enhancers [4–7]. The original TCF1 and LEF1 were each characterized as a set of protein isoforms, differing by the presence or absence of N- terminal (b-catenin) and C-terminal do- mains, none of which were needed for enhancer activity [8–12]. In this issue, Grumolato et al. [13] report that TCF1 and LEF1 have constitutive, elevated activity in leukemia and lymphoma cells. They report that this activity is indepen- dent of b-catenin and instead involves direct recruitment of ATF2 and related family members (Figure 1B). Grumolato et al. describe how the TOPflash reporter for Wnt signaling, a luciferase gene driven by a minimal promoter with multimers of WREs, has elevated constitutive activity in leukemia cell lines. One might assume that this activity derives from TCF/LEF recruit- ment of b-catenin. However, very little stabilized b-catenin could be detected and reporter activity was recapitulated using PLOS Genetics | www.plosgenetics.org truncated forms of TCF1 missing the N- terminal b-catenin–binding domain (iso- forms labelled dominant negatives, or dnTCF/dnLEF [Figure 1A]). In another twist, family member TCF4 could not substitute even though it has a b-catenin– binding domain. This meant that selective action by LEF1 and TCF1 occurred through recruitment of other transcription factors via domains distinct from the b- catenin–binding domain. Using a candi- date approach, the authors tested for functional interactions with proteins that bind AP1 sites. AP1 factors are homo- and heterodimerizing leucine zipper proteins of the Jun, Fos, ATF, and JDP families [14]. Grumolato et al. report that ATF family members (especially ATF2) bind directly to TCF1 and LEF1, not TCF4, and that interactions primarily require the Context Dependent Regulatory domain (CRD; Figure 1A, B). That TCF1/LEF1- ATF2 interactions are detected in multiple types of hematopoietic tumor cell lines suggests that ATF recruitment might account for a significant portion of the ‘‘Wnt reporter activity’’ in these cell types. Knockdown of ATF2 reduced cell growth and lowered expression of TCF1 and LEF1 target genes, similar to effects from overexpression of a dominant negative form of TCF4. Observations such as these suggest that ATF2 is integral to the regulatory role that TCF1/LEF1 play in lymphocytes. These discoveries highlight how TCF1/ LEF1 are closely intertwined with ATF proteins. Indeed, one of the first interac- tions for LEF1 and, later, TCF1 was with proteins that bind an ATF/CREB ele- ment in the T-Cell Receptor alpha chain enhancer (Figure 1D; [4,5]); interestingly, ATF4 was first discovered on the basis of its binding to this element (reviewed in [15]). Additional lymphocyte-specific en- hancers were discovered as collections of ATF/CREB, TCF/LEF, and ETS elements [15]), and functional studies showed that TCF1 and LEF1 cooperated with these proteins bound to neighboring elements to create strong enhancers. Importantly, the b-catenin–binding do- main was entirely dispensable, its deletion enabling even greater activity in some assays [9,12]. Instead, it was the CRD and a strong DNA-bending function of the HMG domain that was of primary importance; DNA bending enabling a three-way, CRD-dependent interaction between TCF/LEFs and other enhancer factors [16]. The exact identities of the ATF/CREB proteins were unknown and were never fully explored. The Grumolato study brings the past back to the present by identifying specific ATF interactors for TCF1 and LEF1 for the first time, and by showing that immune system cancers possess elevated, functional interactions. The current study does not highlight the DNA binding of ATF2 because it appears to be recruited by TCF1/LEF1 to the Wnt reporters in a protein–protein interaction mode. An emerging feature of TCF/LEFs that connects with these findings is a growing recognition of a functional split in the vertebrate family. That is, an increasing number of reports show that TCF4 and a fourth family member, TCF3, function as repressors, or at best, weak activators. More and more frequently it seems that TCF1 and LEF1 operate by opposing TCF3/TCF4 repression and providing strong activation. Since TCF1 and LEF1 Citation: Sprowl S, Waterman ML (2013) Past Visits Present: TCF/LEFs Partner with ATFs for b-Catenin– Independent Activity. PLoS Genet 9(8): e1003745. doi:10.1371/journal.pgen.1003745 Editor: H. Leighton Grimes, Cincinnati Children’s Hospital Medical Center, United States of America Published August 15, 2013 Copyright: s 2013 Sprowl, Waterman. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: The authors received no specific funding for this article. Competing Interests: The authors have declared that no competing interests exist. * E-mail: marian.waterman@uci.edu August 2013 | Volume 9 | Issue 8 | e1003745" @default.
- W2160188581 created "2016-06-24" @default.
- W2160188581 creator A5075612136 @default.
- W2160188581 creator A5091392270 @default.
- W2160188581 date "2013-08-15" @default.
- W2160188581 modified "2023-09-27" @default.
- W2160188581 title "Past Visits Present: TCF/LEFs Partner with ATFs for β-Catenin–Independent Activity" @default.
- W2160188581 cites W1910697241 @default.
- W2160188581 cites W1955427151 @default.
- W2160188581 cites W1981766282 @default.
- W2160188581 cites W1985736574 @default.
- W2160188581 cites W1989215255 @default.
- W2160188581 cites W1990236663 @default.
- W2160188581 cites W2000642611 @default.
- W2160188581 cites W2012870767 @default.
- W2160188581 cites W2026533505 @default.
- W2160188581 cites W2039420678 @default.
- W2160188581 cites W2049904360 @default.
- W2160188581 cites W2066813522 @default.
- W2160188581 cites W2090636859 @default.
- W2160188581 cites W2108808690 @default.
- W2160188581 cites W2109144433 @default.
- W2160188581 cites W2115137176 @default.
- W2160188581 cites W2118811002 @default.
- W2160188581 cites W2127575026 @default.
- W2160188581 cites W2130002948 @default.
- W2160188581 cites W2139146322 @default.
- W2160188581 cites W2143290169 @default.
- W2160188581 cites W2154203460 @default.
- W2160188581 cites W2157954582 @default.
- W2160188581 cites W2164222087 @default.
- W2160188581 cites W2170839692 @default.
- W2160188581 cites W2293706076 @default.
- W2160188581 doi "https://doi.org/10.1371/journal.pgen.1003745" @default.
- W2160188581 hasPubMedCentralId "https://www.ncbi.nlm.nih.gov/pmc/articles/3744446" @default.
- W2160188581 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/23966883" @default.
- W2160188581 hasPublicationYear "2013" @default.
- W2160188581 type Work @default.
- W2160188581 sameAs 2160188581 @default.
- W2160188581 citedByCount "12" @default.
- W2160188581 countsByYear W21601885812014 @default.
- W2160188581 countsByYear W21601885812015 @default.
- W2160188581 countsByYear W21601885812016 @default.
- W2160188581 countsByYear W21601885812019 @default.
- W2160188581 countsByYear W21601885812020 @default.
- W2160188581 crossrefType "journal-article" @default.
- W2160188581 hasAuthorship W2160188581A5075612136 @default.
- W2160188581 hasAuthorship W2160188581A5091392270 @default.
- W2160188581 hasBestOaLocation W21601885811 @default.
- W2160188581 hasConcept C54355233 @default.
- W2160188581 hasConcept C86803240 @default.
- W2160188581 hasConceptScore W2160188581C54355233 @default.
- W2160188581 hasConceptScore W2160188581C86803240 @default.
- W2160188581 hasIssue "8" @default.
- W2160188581 hasLocation W21601885811 @default.
- W2160188581 hasLocation W21601885812 @default.
- W2160188581 hasLocation W21601885813 @default.
- W2160188581 hasLocation W21601885814 @default.
- W2160188581 hasLocation W21601885815 @default.
- W2160188581 hasLocation W21601885816 @default.
- W2160188581 hasOpenAccess W2160188581 @default.
- W2160188581 hasPrimaryLocation W21601885811 @default.
- W2160188581 hasRelatedWork W1828691184 @default.
- W2160188581 hasRelatedWork W1903732681 @default.
- W2160188581 hasRelatedWork W1991523530 @default.
- W2160188581 hasRelatedWork W2002128513 @default.
- W2160188581 hasRelatedWork W2020824267 @default.
- W2160188581 hasRelatedWork W2031436818 @default.
- W2160188581 hasRelatedWork W2057739827 @default.
- W2160188581 hasRelatedWork W2075354549 @default.
- W2160188581 hasRelatedWork W2119103177 @default.
- W2160188581 hasRelatedWork W2092874662 @default.
- W2160188581 hasVolume "9" @default.
- W2160188581 isParatext "false" @default.
- W2160188581 isRetracted "false" @default.
- W2160188581 magId "2160188581" @default.
- W2160188581 workType "article" @default.