CLIPR-59, a new trans-Golgi/TGN cytoplasmic linker protein belonging to the CLIP-170 family

J Cell Biol. 2002 Feb 18;156(4):631-42. doi: 10.1083/jcb.200111003. Epub 2002 Feb 18.

Abstract

The microtubule cytoskeleton plays a fundamental role in cell organization and membrane traffic in higher eukaryotes. It is well established that molecular motors are involved in membrane-microtubule interactions, but it has also been proposed that nonmotor microtubule-binding (MTB) proteins known as CLIPs (cytoplasmic linker proteins) have basic roles in these processes. We report here the characterization of CLIPR-59, a CLIP-170-related protein localized to the trans-most part of the Golgi apparatus. CLIPR-59 contains an acidic region followed by three ankyrin-like repeats and two CLIP-170-related MTB motifs. We show that the 60-amino acid-long carboxy-terminal domain of CLIPR-59 is necessary and sufficient to achieve Golgi targeting, which represents the first identification of a membrane targeting domain in a CLIP-170-related protein. The MTB domain of CLIPR-59 is functional because it localizes to microtubules when expressed as a fragment in HeLa cells. However, our results suggest that this domain is normally inhibited by the presence of adjacent domains, because neither full-length CLIPR-59 nor a CLIPR-59 mutant missing its membrane-targeting region localize to microtubules. Consistent with this observation, overexpression of CLIPR-59 does not affect the microtubule network. However, CLIPR-59 overexpression strongly perturbs early/recycling endosome-TGN dynamics, implicating CLIPR-59 in the regulation of this pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cytoplasm / metabolism
  • DNA, Complementary
  • Endosomes / metabolism
  • Endosomes / physiology
  • Gene Expression
  • HeLa Cells
  • Humans
  • Intracellular Membranes / metabolism
  • Intracellular Membranes / physiology
  • Microtubule-Associated Proteins* / classification
  • Microtubule-Associated Proteins* / genetics
  • Microtubule-Associated Proteins* / metabolism*
  • Microtubules / metabolism
  • Molecular Sequence Data
  • Neoplasm Proteins
  • Rabbits
  • trans-Golgi Network / metabolism*

Substances

  • CLIP3 protein, human
  • DNA, Complementary
  • Microtubule-Associated Proteins
  • Neoplasm Proteins
  • cytoplasmic linker protein 170

Associated data

  • GENBANK/AJ427922