Src-dependent repression of ARF6 is required to maintain podosome-rich sealing zones in bone-digesting osteoclasts

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • Tobias Heckel - , Technische Universität Dresden (Autor:in)
  • Cornelia Czupalla - , Technische Universität Dresden (Autor:in)
  • Ana Isabel Expirto Santo - , Technische Universität Dresden (Autor:in)
  • Mihaela Anitei - , Technische Universität Dresden (Autor:in)
  • Maria Arantzazu Sanchez-Fernandez - , Technische Universität Dresden (Autor:in)
  • Kerstin Mosch - , Technische Universität Dresden (Autor:in)
  • Eberhard Krause - (Autor:in)
  • Bernard Hoflack - , Technische Universität Dresden (Autor:in)

Abstract

Bone digestion occurs when osteoclasts adhere onto bone surfaces and polarize to form acidic, hydrolase-rich resorption lacunae. For this process, they condense their actin-rich podosomes in tight belts to establish sealing zones, which segregate their basal membranes from those facing resorption lacunae. This polarization process remains poorly understood. Here, we combined quantitative proteomics and gene silencing to identify new substrates of the Src tyrosine kinase, a key regulator of osteoclast function. We now report that a depletion of the ARF GTPase-activating protein GIT2, which localizes to sealing zones upon Src phosphorylation, or a lack of GTP hydrolysis on ARF6 impairs sealing zone formation and polarized membrane traffic. Surprisingly, the Rho guanine nucleotide exchange factors α and β PIX, which usually coordinate ARF and Rho signaling, were found to be dispensable. We conclude that the Src-dependent localization of GIT2 is essential for down-regulating ARF6 activity at sealing zones, and thus for maintaining osteoclast polarity.

Details

OriginalspracheEnglisch
Seiten (von - bis)1451-1456
Seitenumfang6
FachzeitschriftProceedings of the National Academy of Sciences of the United States of America : PNAS
Jahrgang106
Ausgabenummer5
PublikationsstatusVeröffentlicht - 3 Feb. 2009
Peer-Review-StatusJa

Externe IDs

PubMed 19164586

Schlagworte

ASJC Scopus Sachgebiete

Schlagwörter

  • GIT2, Podosomes, Polarity, Quantitative proteomics