The small GTPases Rab5a, Rab5b and Rab5c are differentially phosphorylated in vitro

FEBS Lett. 1999 Jun 18;453(1-2):20-4. doi: 10.1016/s0014-5793(99)00686-9.

Abstract

Rab GTPases play a fundamental role in the regulation of membrane traffic. Three different Rab5 isoforms have been reported but no differences in their function in endocytosis have been discovered. As the Rab5 isoforms show a conserved consensus site for Ser/Thr phosphorylation, we investigated whether this site was phosphorylated. Here, we report that the three Rab5 proteins are differentially recognized by different kinases. Rab5a is efficiently phosphorylated by extracellular-regulated kinase 1 but not by extracellular-regulated kinase 2, while cdc2 kinase preferentially phosphorylates Ser-123 of Rab5b. These findings strongly suggest that phosphorylation could be important to differentially regulate the function of the Rab5 isoforms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium-Calmodulin-Dependent Protein Kinases / metabolism*
  • GTP Phosphohydrolases / metabolism*
  • GTP-Binding Proteins / metabolism*
  • Isoenzymes / metabolism
  • JNK Mitogen-Activated Protein Kinases
  • Mitogen-Activated Protein Kinase 3
  • Mitogen-Activated Protein Kinases*
  • Phosphorylation
  • Substrate Specificity
  • rab5 GTP-Binding Proteins

Substances

  • Isoenzymes
  • Calcium-Calmodulin-Dependent Protein Kinases
  • JNK Mitogen-Activated Protein Kinases
  • Mitogen-Activated Protein Kinase 3
  • Mitogen-Activated Protein Kinases
  • GTP Phosphohydrolases
  • GTP-Binding Proteins
  • rab5 GTP-Binding Proteins