Regulation of membrane trafficking by a novel Cdc42-related protein in Caenorhabditis elegans epithelial cells.
Rho GTPases are mainly known for their implication in cytoskeleton remodeling. They have also been recently shown to regulate various aspects of membrane trafficking. Here, we report the identification and the characterization of a novel Caenorhabditis elegans Cdc42-related protein, CRP-1, that shows atypical enzymatic characteristics in vitro. Expression in mouse fibroblasts revealed that, in contrast with CDC-42, CRP-1 was unable to reorganize the actin cytoskeleton and mainly localized to trans-Golgi network and recycling endosomes. This subcellular localization, as well as its expression profile restricted to a subset of epithelial-like cells in C. elegans, suggested a potential function for this protein in polarized membrane trafficking. Consistent with this hypothesis, alteration of CRP-1 expression affected the apical trafficking of CHE-14 in vulval and rectal epithelial cells and sphingolipids (C(6)-NBD-ceramide) uptake and/or trafficking in intestinal cells. However, it did not affect basolateral trafficking of myotactin in the pharynx and the targeting of IFB-2 and AJM-1, two cytosolic apical markers of intestine epithelial cells. Hence, our data demonstrate a function for CRP-1 in the regulation of membrane trafficking in a subset of cells with epithelial characteristics.
Jenna
S
S
Organelle Signaling Laboratory, Department of Surgery, McGill University, Montreal, Quebec, Canada.
Caruso
M-E
ME
Emadali
A
A
Nguyên
D T
DT
Dominguez
M
M
Li
S
S
Roy
R
R
Reboul
J
J
Vidal
M
M
Tzimas
G N
GN
Bossé
R
R
Chevet
E
E
D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport; D017173:Caenorhabditis elegans / Q000737:chemistry / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism; D047108:Embryonic Development; D011992:Endosomes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004847:Epithelial Cells / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D020559:Monomeric GTP-Binding Proteins / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D041681:NIH 3T3 Cells; D010802:Phylogeny; D016415:Sequence Alignment; D020764:cdc42 GTP-Binding Protein / Q000737:chemistry*; D020741:rho GTP-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D021601:trans-Golgi Network / Q000737:chemistry / Q000378:metabolism
D000199:Actins; D029742:Caenorhabditis elegans Proteins; C502924:CRP-1 protein, C elegans; D020559:Monomeric GTP-Binding Proteins; D020764:cdc42 GTP-Binding Protein; D020741:rho GTP-Binding Proteins