RRC ID 80921
Author Rodriguez-Polanco WR, Norris A, Velasco AB, Gleason AM, Grant BD.
Title Syndapin and GTPase RAP-1 control endocytic recycling via RHO-1 and non-muscle myosin II.
Journal Curr Biol
Abstract After endocytosis, many plasma membrane components are recycled via membrane tubules that emerge from early endosomes to form recycling endosomes, eventually leading to their return to the plasma membrane. We previously showed that Syndapin/PACSIN-family protein SDPN-1 is required in vivo for basolateral endocytic recycling in the C. elegans intestine. Here, we document an interaction between the SDPN-1 SH3 domain and a target sequence in PXF-1/PDZ-GEF1/RAPGEF2, a known exchange factor for Rap-GTPases. We found that endogenous mutations engineered into the SDPN-1 SH3 domain, or its binding site in the PXF-1 protein, interfere with recycling in vivo, as does the loss of the PXF-1 target RAP-1. In some contexts, Rap-GTPases negatively regulate RhoA activity, suggesting a potential for Syndapin to regulate RhoA. Our results indicate that in the C. elegans intestine, RHO-1/RhoA is enriched on SDPN-1- and RAP-1-positive endosomes, and the loss of SDPN-1 or RAP-1 elevates RHO-1(GTP) levels on intestinal endosomes. Furthermore, we found that depletion of RHO-1 suppressed sdpn-1 mutant recycling defects, indicating that control of RHO-1 activity is a key mechanism by which SDPN-1 acts to promote endocytic recycling. RHO-1/RhoA is well known for controlling actomyosin contraction cycles, although little is known about the effects of non-muscle myosin II on endosomes. Our analysis found that non-muscle myosin II is enriched on SDPN-1-positive endosomes, with two non-muscle myosin II heavy-chain isoforms acting in apparent opposition. Depletion of nmy-2 inhibited recycling like sdpn-1 mutants, whereas depletion of nmy-1 suppressed sdpn-1 mutant recycling defects, indicating that actomyosin contractility controls recycling endosome function.
Volume 33(22)
Pages 4844-4856.e5
Published 2023-11-20
DOI 10.1016/j.cub.2023.09.051
PII S0960-9822(23)01300-3
PMID 37832552
PMC PMC10841897
MeSH Actomyosin / metabolism Animals Caenorhabditis elegans* / genetics Caenorhabditis elegans* / metabolism Caenorhabditis elegans Proteins* / genetics Caenorhabditis elegans Proteins* / metabolism Endocytosis / physiology Endosomes / metabolism GTP Phosphohydrolases / metabolism Myosin Type II / metabolism
Resource
C.elegans tm861