RRC ID 65337
Author Zein-Sabatto H, Cole T, Hoang HD, Tiwary E, Chang C, Miller MA.
Title The type II integral ER membrane protein VAP-B homolog in C. elegans is cleaved to release the N-terminal MSP domain to signal non-cell-autonomously.
Journal Dev Biol
Abstract VAMP/synaptobrevin-associated protein B (VAP-B) is a type II ER membrane protein, but its N-terminal MSP domain (MSPd) can be cleaved and secreted. Mutations preventing the cleavage and secretion of MSPd have been implicated in cases of human neurodegenerative diseases. The site of VAP cleavage and the tissues capable in releasing the processed MSPd are not understood. In this study, we analyze the C. elegans VAP-B homolog, VPR-1, for its processing and secretion from the intestine. We show that intestine-specific expression of an N-terminally FLAG-tagged VPR-1 rescues underdeveloped gonad and sterility defects in vpr-1 null hermaphrodites. Immunofluorescence studies reveal that the tagged intestinal expressed VPR-1 is present at the distal gonad. Mass spectrometry analysis of a smaller product of the N-terminally tagged VPR-1 identifies a specific cleavage site at Leu156. Mutation of the leucine results in loss of gonadal MSPd signal and reduced activity of the mutant VPR-1. Thus, we report for the first time the cleavage site of VPR-1 and provide direct evidence that intestinally expressed VPR-1 can be released and signal in the distal gonad. These results establish the foundation for further exploration of VAP cleavage, MSPd secretion, and non-cell-autonomous signaling in development and diseases.
Volume 470
Pages 10-20
Published 2021-2-1
DOI 10.1016/j.ydbio.2020.10.015
PII S0012-1606(20)30292-X
PMID 33160939
PMC PMC7856274
MeSH Animals Animals, Genetically Modified Caenorhabditis elegans / embryology Caenorhabditis elegans / genetics Caenorhabditis elegans / growth & development Caenorhabditis elegans / metabolism* Caenorhabditis elegans Proteins / chemistry Caenorhabditis elegans Proteins / genetics Caenorhabditis elegans Proteins / metabolism* Endoplasmic Reticulum / metabolism Genes, Helminth Gonads / chemistry Gonads / growth & development Gonads / metabolism Helminth Proteins / chemistry Helminth Proteins / metabolism* Hermaphroditic Organisms / genetics Hermaphroditic Organisms / metabolism Hermaphroditic Organisms / physiology Infertility Intestines / cytology Intestines / physiology Leucine / metabolism Membrane Proteins / chemistry Membrane Proteins / genetics Membrane Proteins / metabolism* Phenotype Point Mutation Protein Domains Protein Processing, Post-Translational
Resource
C.elegans