The ARF GAP ELMOD2 acts with different GTPases to regulate centrosomal microtubule nucleation and cytokinesis

Mol Biol Cell. 2020 Aug 15;31(18):2070-2091. doi: 10.1091/mbc.E20-01-0012. Epub 2020 Jul 2.

Abstract

ELMOD2 is a ∼32 kDa protein first purified by its GTPase-activating protein (GAP) activity toward ARL2 and later shown to have uniquely broad specificity toward ARF family GTPases in in vitro assays. To begin the task of defining its functions in cells, we deleted ELMOD2 in immortalized mouse embryonic fibroblasts and discovered a number of cellular defects, which are reversed upon expression of ELMOD2-myc. We show that these defects, resulting from the loss of ELMOD2, are linked to two different pathways and two different GTPases: with ARL2 and TBCD to support microtubule nucleation from centrosomes and with ARF6 in cytokinesis. These data highlight key aspects of signaling by ARF family GAPs that contribute to previously underappreciated sources of complexity, including GAPs acting from multiple sites in cells, working with multiple GTPases, and contributing to the spatial and temporal control of regulatory GTPases by serving as both GAPs and effectors.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • ADP-Ribosylation Factors / metabolism
  • Animals
  • Cell Culture Techniques
  • Centrosome / metabolism
  • Cytokinesis / physiology*
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / metabolism*
  • Cytoskeletal Proteins / physiology
  • Fibroblasts / metabolism
  • GTP-Binding Proteins / metabolism
  • GTPase-Activating Proteins / metabolism
  • Mice
  • Microtubule-Associated Proteins / metabolism
  • Microtubules / metabolism*
  • Mitochondria / metabolism
  • Mouse Embryonic Stem Cells / metabolism

Substances

  • Cytoskeletal Proteins
  • ELMOD2 protein, mouse
  • GTPase-Activating Proteins
  • Microtubule-Associated Proteins
  • Arl2 protein, mouse
  • GTP-Binding Proteins
  • ADP-Ribosylation Factors