Molecular and Cellular Biochemistry

, Volume 271, Issue 1, pp 77–90

Angiotensin II stimulated transcription of cyclooxygenase II is regulated by a novel kinase cascade involving Pyk2, MEKK4 and annexin II

  • Zachary E. Derbyshire
  • Ursula M. Halfter
  • Ronald L. Heimark
  • Terence H. Sy
  • Richard R. Vaillancourt

DOI: 10.1007/s11010-005-5386-9

Cite this article as:
Derbyshire, Z.E., Halfter, U.M., Heimark, R.L. et al. Mol Cell Biochem (2005) 271: 77. doi:10.1007/s11010-005-5386-9


Although it is known that MEKK4 regulates MKK6, and p38 MAP kinase, extracellular stimuli that activate the serine/threonine kinase, MEKK4, are unknown. The aim of this study was then to identify stimuli that regulate MEKK4. By using recombinant MEKK4, as bait to attract interacting proteins, the calcium binding protein, annexin II, was identified by mass spectrometry as interacting with MEKK4, suggesting that MEKK4 might be regulated by calcium. A calcium-dependent interaction between MEKK4 and annexin II was observed when MEKK4 was immunoprecipitated from rat aortic smooth muscle cells that were treated with angiotensin II. Additional studies using recombinant MEKK4 in a Far-Western immunoblot identified a protein of 120 kDa as interacting directly with MEKK4. Prior studies indicated that MEKK4 was phosphorylated on tyrosine in vivo, and in fact, Pyk2 interacts with MEKK4 in an angiotensin II dependent manner in rat aortic smooth muscle cells. Pyk2 phosphorylates MEKK4 in vitro and Pyk2-dependent phosphorylation further regulates MEKK4-dependent phosphorylation of MKK6. Finally, dominant-negative MEKK4 inhibits angiotensin II mediated transcription of a luciferase reporter construct containing the cyclooxygenase II promoter, demonstrating that MEKK4 functions in a calcium-dependent manner as a substrate for Pyk2 and regulates transcription of cyclooxygenase II. (Mol Cell Biochem 271: 77–90, 2005)

Key words

MEKK4 Pyk2 cyclooxygenase II annexin II angiotensin II p38 MAP kinase insect cells 



mitogen-activated protein kinase


extracellular-regulated protein kinase


MAPK/ERK kinase kinase


proline-rich tyrosine kinase 2


cyclooxygenase II


glutathione S-transferase


polyacrylamide gel electrophoresis

Copyright information

© Springer Science + Business Media, Inc. 2005

Authors and Affiliations

  • Zachary E. Derbyshire
    • 1
  • Ursula M. Halfter
    • 1
  • Ronald L. Heimark
    • 2
  • Terence H. Sy
    • 1
  • Richard R. Vaillancourt
    • 1
    • 3
  1. 1.Department of Pharmacology and ToxicologyUniversity of ArizonaTucsonUSA
  2. 2.Department of Surgery, and Cell Biology and AnatomyUniversity of ArizonaTucsonUSA
  3. 3.College of PharmacyUniversity of ArizonaTucsonU.S.A.