RRC ID 11366
Author Kita A, Li C, Yu Y, Umeda N, Doi A, Yasuda M, Ishiwata S, Taga A, Horiuchi Y, Sugiura R.
Title Role of the Small GTPase Rho3 in Golgi/Endosome trafficking through functional interaction with adaptin in Fission Yeast.
Journal PLoS ONE
Abstract BACKGROUND:We had previously identified the mutant allele of apm1(+) that encodes a homolog of the mammalian µ1A subunit of the clathrin-associated adaptor protein-1 (AP-1) complex, and we demonstrated the role of Apm1 in Golgi/endosome trafficking, secretion, and vacuole fusion in fission yeast.
METHODOLOGY/PRINCIPAL FINDINGS:In the present study, we isolated rho3(+), which encodes a Rho-family small GTPase, an important regulator of exocystosis, as a multicopy-suppressor of the temperature-sensitive growth of the apm1-1 mutant cells. Overexpression of Rho3 suppressed the Cl(-) sensitivity and immunosuppressant sensitivity of the apm1-1 mutant cells. Overexpression of Rho3 also suppressed the fragmentation of vacuoles, and the accumulation of v-SNARE Syb1 in Golgi/endosomes and partially suppressed the defective secretion associated with apm1-deletion cells. Notably, electron microscopic observation of the rho3-deletion cells revealed the accumulation of abnormal Golgi-like structures, vacuole fragmentation, and accumulation of secretory vesicles; these phenotypes were very similar to those of the apm1-deletion cells. Furthermore, the rho3-deletion cells and apm1-deletion cells showed very similar phenotypic characteristics, including the sensitivity to the immunosuppressant FK506, the cell wall-damaging agent micafungin, Cl(-), and valproic acid. Green fluorescent protein (GFP)-Rho3 was localized at Golgi/endosomes as well as the plasma membrane and division site. Finally, Rho3 was shown to form a complex with Apm1 as well as with other subunits of the clathrin-associated AP-1 complex in a GTP- and effector domain-dependent manner.
CONCLUSIONS/SIGNIFICANCE:Taken together, our findings reveal a novel role of Rho3 in the regulation of Golgi/endosome trafficking and suggest that clathrin-associated adaptor protein-1 and Rho3 co-ordinate in intracellular transport in fission yeast. To the best of our knowledge, this study provides the first evidence of a direct link between the small GTPase Rho and the clathrin-associated adaptor protein-1 in membrane trafficking.
Volume 6(2)
Pages e16842
Published 2011-2-3
DOI 10.1371/journal.pone.0016842
PMID 21304827
PMC PMC3033427
MeSH Adaptor Protein Complex 1 / genetics Adaptor Protein Complex 1 / metabolism* Adaptor Protein Complex mu Subunits / genetics Adaptor Protein Complex mu Subunits / metabolism* Amino Acid Sequence Biological Transport / genetics Endosomes / genetics Endosomes / metabolism* Golgi Apparatus / genetics Golgi Apparatus / metabolism* Molecular Sequence Data Organisms, Genetically Modified Protein Binding Schizosaccharomyces / enzymology Schizosaccharomyces / genetics* Schizosaccharomyces / metabolism* Schizosaccharomyces pombe Proteins / genetics Schizosaccharomyces pombe Proteins / metabolism* Schizosaccharomyces pombe Proteins / physiology* rho GTP-Binding Proteins / genetics rho GTP-Binding Proteins / metabolism* rho GTP-Binding Proteins / physiology*
IF 2.776
Times Cited 11
Yeast Genome DNA clones