Golgi-specific DHHC zinc finger protein GODZ mediates membrane Ca2+ transport

J Biol Chem. 2010 Feb 12;285(7):4621-8. doi: 10.1074/jbc.M109.069849. Epub 2009 Dec 2.

Abstract

The Golgi-specific zinc finger protein GODZ (palmitoyl acyltransferase/DHHC-3) mediates the palmitoylation and post-translational modification of many protein substrates that regulate membrane-protein interactions. Here, we show that GODZ also mediates Ca(2+) transport in expressing Xenopus laevis oocytes. Two-electrode voltage-clamp, fluorescence, and (45)Ca(2+) isotopic uptake determinations demonstrated voltage- and concentration-dependent, saturable, and substrate-inhibitable Ca(2+) transport in oocytes expressing GODZ cRNA but not in oocytes injected with water alone. Moreover, we show that GODZ-mediated Ca(2+) transport is regulated by palmitoylation, as the palmitoyl acyltransferase inhibitor 2-bromopalmitate or alteration of the acyltransferase DHHC motif (GODZ-DHHS) diminished GODZ-mediated Ca(2+) transport by approximately 80%. The GODZ mutation V61R abolished Ca(2+) transport but did not affect palmitoyl acyltransferase activity. Coexpression of GODZ-V61R with GODZ-DHHS restored GODZ-DHHS-mediated Ca(2+) uptake to values observed with wild-type GODZ, excluding an endogenous effect of palmitoylation. Coexpression of an independent palmitoyl acyltransferase (HIP14) with the GODZ-DHHS mutant also rescued Ca(2+) transport. HIP14 did not mediate Ca(2+) transport when expressed alone. Immunocytochemistry studies showed that GODZ and HIP14 co-localized to the Golgi and the same post-Golgi vesicles, suggesting that heteropalmitoylation might play a physiological role in addition to a biochemical function. We conclude that GODZ encodes a Ca(2+) transport protein in addition to its ability to palmitoylate protein substrates.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyltransferases / chemistry
  • Acyltransferases / genetics
  • Acyltransferases / metabolism*
  • Adaptor Proteins, Signal Transducing / chemistry
  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism
  • Amino Acid Motifs / genetics
  • Amino Acid Motifs / physiology
  • Amino Acid Sequence
  • Animals
  • COS Cells
  • Calcium / metabolism*
  • Chlorocebus aethiops
  • Golgi Apparatus / metabolism*
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Humans
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice
  • Microscopy, Confocal
  • Molecular Sequence Data
  • Nerve Tissue Proteins / chemistry
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism
  • Oocytes
  • Protein Transport / genetics
  • Protein Transport / physiology
  • Xenopus / genetics
  • Xenopus / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • GODZ protein, mouse
  • Membrane Proteins
  • Nerve Tissue Proteins
  • Green Fluorescent Proteins
  • Acyltransferases
  • ZDHHC17 protein, human
  • Calcium