Expression of VACM-1 protein in cultured rat adrenal endothelial cells is linked to the cell cycle

Endothelium. 2001;8(1):49-63. doi: 10.3109/10623320109063157.


The vasopressin-activated calcium-mobilizing (VACM-1) protein is a unique arginine vasopressin (AVP) receptor which shares sequence homology with the cullins, genes involved in the regulation of cell cycle transitions. Unlike either cullins or AVP receptors, however, VACM-1 is expressed exclusively in the vascular endothelial cells and in the renal collecting tubule cells. In order to test the hypothesis that the expression of VACM-1 might be correlated with the cell cycle, and to establish an endothelial cell model for the VACM-1 receptor, we examined VACM-1 expression in rat adrenal medulla endothelial cells (RAMEC). Northern and Western blot analyses of mRNA and protein from RAMEC identified presence of 6.4 kb mRNA and a Mr 81 kDa protein, respectively. Immunostaining of RAMEC with anti-VACM-1 antibodies and Western blot analyses indicated that in RAMEC, VACM-1 protein expression is dependent on the cell cycle. VACM-1 protein virtually disappears during the S phase and localizes to the cytosol during cell division and to the cell membrane at the completion of cytokinesis. Furthermore, pretreatment of RAMEC with anti-VACM-1 specific antibodies increased basal levels of Ca2+and attenuated the AVP-dependent increase in cytosolic Ca2+. In summary, these results indicate that VACM-1 protein expression in RAMEC membrane is linked to the cell cycle, and consequently, VACM-1 may be involved in the regulation of cell division.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adrenal Medulla / cytology
  • Adrenal Medulla / physiology*
  • Animals
  • Aphidicolin / pharmacology
  • Calcium Signaling / physiology
  • Cell Cycle / drug effects
  • Cell Cycle / physiology*
  • Cell Membrane / physiology
  • Cell Nucleus / physiology
  • Cells, Cultured
  • Cullin Proteins*
  • Endothelium / cytology
  • Endothelium / physiology
  • Gene Expression Regulation / drug effects
  • Gene Expression Regulation / physiology*
  • Immunohistochemistry
  • Membrane Proteins / genetics*
  • Rats
  • Receptors, Vasopressin / genetics*
  • Transcription, Genetic*


  • Cul5 protein, rat
  • Cullin Proteins
  • Membrane Proteins
  • Receptors, Vasopressin
  • Aphidicolin