An Arf-GAP promotes endocytosis and hyphal growth of Ashbya gossypii. Issue 24 (7th November 2017)

• Record Type: Journal Article
• Authors: Oscarsson, Therese; Walther, Andrea; Lengeler, Klaus B; Wendland, Jürgen
• Is Part Of: FEMS microbiology letters. Volume 364:Issue 24(2017)
• Publication Date: 2017-11-07
• Subjects: ARF3 -- actin cytoskeleton -- functional analysis; Microbiology -- Periodicals; 579
• DOI: 10.1093/femsle/fnx240
• Languages: English
• ISSNs: 0378-1097

Abstract

Abstract: The ADP-ribosylation factor (ARF) family of GTPases are highly conserved from yeast to human and regulate vesicle budding. Sec7 domain containing proteins stimulate the guanine nucleotide exchange on Arf proteins, while ARF-GTPase activating proteins stimulate the hydrolysis of GTP. Since vesicle trafficking is important for hyphal growth, we studied the Ashbya gossypii homolog of Saccharomyces cerevisiae ARF3 along with its putative GEF and GTPase-activating protein (GAP) encoded by YEL1 and GTS1, respectively. Deletion of YEL1 had no discernible phenotype and deletion of ARF3 had only a minor defect in vacuolar fusion. In contrast, deletion of GTS1 severely impaired hyphal growth, and mutants showed defects in the maintenance of polarity and the localization of cortical actin patches. The uptake of the lipophilic dye FM4-64 was delayed in gts1 hyphae, indicating a defect in endocytosis. Gts1 has several protein domains, of which the Arf-GAP domain is required for complementation of the gts1 mutant phenotype. GFP -tagged GTS1 under control of its endogenous promoter localized to the plasma membrane but was enriched at hyphal tips and septal sites corresponding to a role in polarized vesicle trafficking. Our results indicate that this ARF-GTPase module plays an important role for filamentous hyphal growth. Abstract : Analysis of the ARF3-GTPase module in Ashbya gossypii identified the Arf3-GAP GTS1 as a promoter of polarized hyphal growth and endocytosis. Mutant gts1 hyphae showed actin cytoskeleton defects.