Matches in SemOpenAlex for { <https://semopenalex.org/work/W2896913429> ?p ?o ?g. }
Showing items 1 to 68 of
68
with 100 items per page.
- W2896913429 abstract "Phosphoinositides are key lipid signaling molecules present in membranes of all eukaryotes. Different species of phosphoinositides serve as membrane signposts at distinct cellular compartments. This assymetric distribution of phosphoinositides is achieved by the presence of an elaborate set of lipid kinases and phosphatases operating at specific organelle membranes. The lipid phosphatase SAC1 is found in both endoplasmic reticulum (ER) and Golgi. Similar to yeast Sac1p, human SAC1 (hSAC1) is the major phosphatidylinositol-4-phosphatase (PI(4)P-phosphatase). Distinct localization of hSAC1 in both ER and Golgi membranes suggests that this PI(4)P-phosphatase has compartment specific roles in regulating steady state distribution of PI(4)P in these organelles. OCRL1 is a Golgi and endosomal localized PI(4,5)P2 5-phosphatase that is implicated in a severe X-linked disease, Lowe syndrome, which is characterized by congenital cataracts, Fanconi syndrome and mental retardation. How mutations in OCRL1 cause Lowe syndrome is unknown. The functional analysis of hSAC1 and OCRL1 in regulating Golgi PI(4)P and PI(4,5)P2 is the main focus of this work. Confocal immunofluorescence and immuno-electron microscopy (immuno-EM) show that PI(4)P and hSAC1 form an opposing gradient in the Golgi. hSAC1 is highly enriched at Golgi cisternal membranes while PI(4)P is concentrated at the trans-Golgi network (TGN) where cargo proteins are packaged and exported. Golgi enzymes such as N-acetylglucosaminyltransferase I (NacT1) and mannosidase II (ManII) are preferentially found in these PI(4)P-depleted areas. siRNA-mediated knock-down of hSAC1 leads to accumulation of PI(4)P at Golgi, plasma membrane and endosomal like structures and causes mislocalization of ManII and NacT1. This data suggests that SAC1 establishes PI(4)P-depleted Golgi regions that are important for proper localization and recycling of Golgi resident enzymes. Conversely, depletion of OCRL1 does not disturb Golgi morphology or induce mislocalization of Golgi resident enzymes. However, bulk secretion is inhibited in OCRL1 depleted cells. The OCRL1-b splice variant populates TGN and early endosomal compartment whereas the OCRL1-a splice variant containing an extra 8 amino acid acidic cluster is found only in a subset of late endosomal/ lysosomal membranes. This distinct localization of OCRL1 splice variants indicates that each isoform might regulate different trafficking routes by regulating PI(4,5)P2 levels at these compartments. Together, the results show that hSAC1 and OCRL1 establish distinct phosphoinositide-specific domains within the Golgi that are instrumental for segregation of anterograde trafficking from the recycling of resident Golgi enzymes." @default.
- W2896913429 created "2018-10-26" @default.
- W2896913429 creator A5042240991 @default.
- W2896913429 date "2007-01-01" @default.
- W2896913429 modified "2023-09-23" @default.
- W2896913429 title "Regulation of lipid signaling at the Golgi by the lipid phosphatases hSAC1 and OCRL1" @default.
- W2896913429 doi "https://doi.org/10.11588/heidok.00007101" @default.
- W2896913429 hasPublicationYear "2007" @default.
- W2896913429 type Work @default.
- W2896913429 sameAs 2896913429 @default.
- W2896913429 citedByCount "0" @default.
- W2896913429 crossrefType "dissertation" @default.
- W2896913429 hasAuthorship W2896913429A5042240991 @default.
- W2896913429 hasConcept C102747710 @default.
- W2896913429 hasConcept C119062480 @default.
- W2896913429 hasConcept C11960822 @default.
- W2896913429 hasConcept C158617107 @default.
- W2896913429 hasConcept C168240541 @default.
- W2896913429 hasConcept C171321305 @default.
- W2896913429 hasConcept C178666793 @default.
- W2896913429 hasConcept C184235292 @default.
- W2896913429 hasConcept C2780610907 @default.
- W2896913429 hasConcept C2910033705 @default.
- W2896913429 hasConcept C55493867 @default.
- W2896913429 hasConcept C79879829 @default.
- W2896913429 hasConcept C86803240 @default.
- W2896913429 hasConcept C95444343 @default.
- W2896913429 hasConceptScore W2896913429C102747710 @default.
- W2896913429 hasConceptScore W2896913429C119062480 @default.
- W2896913429 hasConceptScore W2896913429C11960822 @default.
- W2896913429 hasConceptScore W2896913429C158617107 @default.
- W2896913429 hasConceptScore W2896913429C168240541 @default.
- W2896913429 hasConceptScore W2896913429C171321305 @default.
- W2896913429 hasConceptScore W2896913429C178666793 @default.
- W2896913429 hasConceptScore W2896913429C184235292 @default.
- W2896913429 hasConceptScore W2896913429C2780610907 @default.
- W2896913429 hasConceptScore W2896913429C2910033705 @default.
- W2896913429 hasConceptScore W2896913429C55493867 @default.
- W2896913429 hasConceptScore W2896913429C79879829 @default.
- W2896913429 hasConceptScore W2896913429C86803240 @default.
- W2896913429 hasConceptScore W2896913429C95444343 @default.
- W2896913429 hasLocation W28969134291 @default.
- W2896913429 hasOpenAccess W2896913429 @default.
- W2896913429 hasPrimaryLocation W28969134291 @default.
- W2896913429 hasRelatedWork W133058841 @default.
- W2896913429 hasRelatedWork W1535587662 @default.
- W2896913429 hasRelatedWork W1965043023 @default.
- W2896913429 hasRelatedWork W2016767899 @default.
- W2896913429 hasRelatedWork W2038816032 @default.
- W2896913429 hasRelatedWork W2042723108 @default.
- W2896913429 hasRelatedWork W2043299973 @default.
- W2896913429 hasRelatedWork W2075568323 @default.
- W2896913429 hasRelatedWork W2079940927 @default.
- W2896913429 hasRelatedWork W2088679015 @default.
- W2896913429 hasRelatedWork W2113624016 @default.
- W2896913429 hasRelatedWork W2147578072 @default.
- W2896913429 hasRelatedWork W2159447933 @default.
- W2896913429 hasRelatedWork W2165075168 @default.
- W2896913429 hasRelatedWork W2255588409 @default.
- W2896913429 hasRelatedWork W2779330557 @default.
- W2896913429 hasRelatedWork W2894674942 @default.
- W2896913429 hasRelatedWork W2900278848 @default.
- W2896913429 hasRelatedWork W2935718787 @default.
- W2896913429 hasRelatedWork W3081087801 @default.
- W2896913429 isParatext "false" @default.
- W2896913429 isRetracted "false" @default.
- W2896913429 magId "2896913429" @default.
- W2896913429 workType "dissertation" @default.