CVAK104 is a novel regulator of clathrin-mediated SNARE sorting

Traffic. 2007 Jul;8(7):893-903. doi: 10.1111/j.1600-0854.2007.00576.x.

Abstract

Clathrin-coated vesicles (CCVs) mediate transport between the plasma membrane, endosomes and the trans Golgi network. Using comparative proteomics, we have identified coated-vesicle-associated kinase of 104 kDa (CVAK104) as a candidate accessory protein for CCV-mediated trafficking. Here, we demonstrate that the protein colocalizes with clathrin and adaptor protein-1 (AP-1), and that it is associated with a transferrin-positive endosomal compartment. Consistent with these observations, clathrin as well as the cargo adaptors AP-1 and epsinR can be coimmunoprecipitated with CVAK104. Small interfering RNA (siRNA) knockdown of CVAK104 in HeLa cells results in selective loss of the SNARE proteins syntaxin 8 and vti1b from CCVs. Morpholino-mediated knockdown of CVAK104 in Xenopus tropicalis causes severe developmental defects, including a bent body axis and ventral oedema. Thus, CVAK104 is an evolutionarily conserved protein involved in SNARE sorting that is essential for normal embryonic development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Vesicular Transport / metabolism
  • Animals
  • Biological Transport
  • Cell Membrane / metabolism
  • Clathrin / metabolism*
  • Endosomes / metabolism
  • Evolution, Molecular
  • HeLa Cells
  • Humans
  • Mice
  • Protein Serine-Threonine Kinases / physiology*
  • Qa-SNARE Proteins / metabolism
  • RNA, Small Interfering / metabolism
  • SNARE Proteins / metabolism*
  • Xenopus / metabolism

Substances

  • Adaptor Proteins, Vesicular Transport
  • CLINT1 protein, human
  • Clathrin
  • Qa-SNARE Proteins
  • RNA, Small Interfering
  • SNARE Proteins
  • Protein Serine-Threonine Kinases
  • SCYL2 protein, human