1. Academic Validation
  2. GOLPH3 bridges phosphatidylinositol-4- phosphate and actomyosin to stretch and shape the Golgi to promote budding

GOLPH3 bridges phosphatidylinositol-4- phosphate and actomyosin to stretch and shape the Golgi to promote budding

  • Cell. 2009 Oct 16;139(2):337-51. doi: 10.1016/j.cell.2009.07.052.
Holly C Dippold 1 Michelle M Ng Suzette E Farber-Katz Sun-Kyung Lee Monica L Kerr Marshall C Peterman Ronald Sim Patricia A Wiharto Kenneth A Galbraith Swetha Madhavarapu Greg J Fuchs Timo Meerloo Marilyn G Farquhar Huilin Zhou Seth J Field
Affiliations

Affiliation

  • 1 Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0707, USA.
Abstract

Golgi membranes, from yeast to humans, are uniquely enriched in phosphatidylinositol-4-phosphate (PtdIns(4)P), although the role of this lipid remains poorly understood. Using a proteomic lipid-binding screen, we identify the Golgi protein GOLPH3 (also called GPP34, GMx33, MIDAS, or yeast Vps74p) as a PtdIns(4)P-binding protein that depends on PtdIns(4)P for its Golgi localization. We further show that GOLPH3 binds the unconventional Myosin MYO18A, thus connecting the Golgi to F-actin. We demonstrate that this linkage is necessary for normal Golgi trafficking and morphology. The evidence suggests that GOLPH3 binds to PtdIns(4)P-rich trans-Golgi membranes and MYO18A conveying a tensile force required for efficient tubule and vesicle formation. Consequently, this tensile force stretches the Golgi into the extended ribbon observed by fluorescence microscopy and the familiar flattened form observed by electron microscopy.

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