| Status | 已發表Published |
| Modifier screens of a C. elegans tubular polarity phenotype identify components of a novel vesicle-based pathway for polarized membrane biogenesis | |
Zhang, N.; Zhang, H. ; Khan, L.; Gobel, V.
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| 2015-06-24 | |
| Source Publication | 20th International C. elegans Conference Full Abstracts
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| Abstract | We and others previously showed that apical domain and lumen positions in the C. elegans intestine depend on membrane glycosphingolipids (GSLs), clathrin and its AP-1 adaptor, suggesting a novel vesicle-based pathway for polarized membrane biogenesis. To delineate this pathway, we performed genetic interaction screens between these and 57 trafficking molecules identified in our prior multi- and unicellular tubulogenesis screens as being required for apical membrane biogenesis.One modifier screen assessed intestinal polarity in GSL-depleted let-767(s2819; sDp3) mutants that appear wild-type in the presence of the balancer sDp3, but display an apical polarity inversion phenotype in its absence (apical markers displaced basolaterally; ectopic lateral lumen formation). RNAi with 11/57 genes basolaterally displaced ERM-1::GFP in animals with sDp3 (enhancement), whereas RNAi with 5/57 genes reduced the amount of basolateral displacement and ectopic lumen formation in animals without sDp3 (suppression). Most modifiers are well-known trafficking components not yet implicated in polarized trafficking. To explore the seeming paradox that the loss of vesicle components needed for apical membrane biogenesis suppressed an apical polarity defect, we characterized two suppressors: the adaptor protein DAB-1, previously implicated in clathrin-dependent endocytosis, and the GTPase RAB-7, well-characterized in lysosome-directed trafficking. GFP fusions of these essential proteins localized to intestinal vesicles, consistent with a vesicle-based function in intestinal polarity. Confocal analysis of labeled polarized plasma membrane components showed that the depletion of each suppressor, to different degrees, abnormally retained apical plasma membrane markers (e.g. ERM-1) on cytoplasmic vacuoles, while one of two (RAB-7) also displaced basolateral plasma membrane markers (e.g. SLCF-1) to cytoplasmic vesicles. Moreover, tracking various GFP-labeled vesicle populations revealed that the loss of each suppressor also interfered with presumed basolateral-membrane directed carriers. dab-1 RNAi most strongly affected basolateral carriers and apical cargo, and rab-7 RNAi predominantly disturbed basolateral cargo delivery. Our findings suggest a scenario where the loss of suppressors relieves the GSL-dependent apical polarity inversion by reducing distinct facets of apical cargo targeting to the basolateral membrane, consistent with a transcytotic route to the apical membrane or en route sorting stations. |
| Keyword | Modifier Screens Tubular polarity vesicle-based pathway membrane biogenesis |
| URL | View the original |
| Language | 英語English |
| The Source to Article | PB_Publication |
| PUB ID | 14675 |
| Document Type | Conference paper |
| Collection | DEPARTMENT OF BIOMEDICAL SCIENCES Faculty of Health Sciences |
| Recommended Citation GB/T 7714 | Zhang, N.,Zhang, H.,Khan, L.,et al. Modifier screens of a C. elegans tubular polarity phenotype identify components of a novel vesicle-based pathway for polarized membrane biogenesis[C], 2015. |
| APA | Zhang, N.., Zhang, H.., Khan, L.., & Gobel, V. (2015). Modifier screens of a C. elegans tubular polarity phenotype identify components of a novel vesicle-based pathway for polarized membrane biogenesis. 20th International C. elegans Conference Full Abstracts. |
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