Premium
Clathrin Interaction and Subcellular Localization of Ce‐DAB‐1, an Adaptor for Protein Secretion in Caenorhabditis elegans
Author(s) -
Kamikura Darren M.,
Cooper Jonathan A.
Publication year - 2006
Publication title -
traffic
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.677
H-Index - 130
eISSN - 1600-0854
pISSN - 1398-9219
DOI - 10.1111/j.1600-0854.2006.00386.x
Subject(s) - biology , clathrin , microbiology and biotechnology , secretion , clathrin adaptor proteins , caenorhabditis elegans , signal transducing adaptor protein , rab , golgi apparatus , receptor , endocytosis , signal transduction , biochemistry , endoplasmic reticulum , gene , gtpase
Growth factors must be secreted appropriately to co‐ordinate cell proliferation, specification and movement during development and to control cell numbers and migrations in adult animals. Previous results showed that the secretion of the Caenorhabditis elegans fibroblast growth factor homologue, EGL‐17, from vulval precursor cells in vivo involves the cytoplasmic adaptor protein Ce‐DAB‐1 and two lipoprotein receptors that bind Ce‐DAB‐1 and EGL‐17. Here, we confirm the Ce‐DAB‐1 requirement for EGL‐17 secretion using mutant animals. In vitro , Ce‐DAB‐1 binds to clathrin and APT‐4, the C. elegans homologue of the α‐adaptin subunit of adaptor protein 2 (AP2), and weakly to the γ‐appendage domains of APT‐1 (AP1γ‐adaptin) and APT‐9 (GGA protein). In tissue‐culture cells, Ce‐DAB‐1 localizes to various compartments, including AP2‐containing vesicles near the cell surface and perinuclear vesicles that contain AP1. The latter also contain Rab8, but not Rab5 or Rab11, as well as proteins en route from the trans Golgi network (TGN) to the surface. In vivo , EGL‐17 secretion was inhibited by depletion of apt‐1, apt‐9 or ce‐rab‐8 and partially inhibited by RNAi of ce‐rab‐5 , consistent with an important role for these proteins in the secretion of EGL‐17 in vivo . These results suggest that Ce‐DAB‐1 might co‐ordinate the assembly of endocytic or secretory vesicles in vivo and may mediate EGL‐17 secretion directly, by recruiting clathrin to lipoprotein receptors at the TGN, or indirectly, by affecting lipoprotein receptor endocytosis and recycling.