A growth-dependent post-translational modification of annexin VI

Biochim Biophys Acta. 1992 Nov 10;1160(1):120-6. doi: 10.1016/0167-4838(92)90045-f.


Annexin VI (p68, 67-kDa calelectrin) is a member of a family of Ca2+/phospholipid-binding proteins, that includes p35 (annexin I) and p36 (annexin II), the major cellular substrates for phosphorylation by the epidermal growth factor receptor and pp60v-src tyrosine kinase activities, respectively. We report here that like annexins I and II, annexin VI is phosphorylated in vivo, but that in contrast, annexin VI phosphorylation is associated with cell growth. In both Swiss 3T3 fibroblasts and human T-lymphoblasts the pattern of phosphorylation followed an almost identical profile. In particular, annexin VI was not phosphorylated in quiescent cells, but was phosphorylated on serine and to a lesser extent threonine, several hours following cell stimulation. Furthermore, annexin VI also incorporated phosphate in a growth-dependent manner, in a form other than a phosphoamino-acid. The phosphate was visualised following acid hydrolysis of immunoprecipitated annexin VI, as part of a complex having high mobility on 2-D thin-layer electrophoresis. The identity of this complex is not known. The results suggest that a post-translational modification other than direct protein phosphorylation may influence the activity of annexin VI and provide evidence linking cell growth with regulation of annexin VI function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3 Cells
  • Animals
  • Annexin A6 / biosynthesis
  • Annexin A6 / genetics
  • Annexin A6 / metabolism*
  • Cell Line
  • Growth Substances / pharmacology
  • Humans
  • Lymphocytes
  • Mice
  • Mitotic Index
  • Phosphorylation
  • Phosphoserine / analysis
  • Phosphothreonine / analysis
  • Protein Biosynthesis*


  • Annexin A6
  • Growth Substances
  • Phosphothreonine
  • Phosphoserine