The Ca2+/Calmodulin-dependent Protein Kinase Kinases Are AMP-activated Protein Kinase Kinases

The AMP-activated protein kinase (AMPK) is an important regulator of cellular metabolism in response to metabolic stress and to other regulatory signals. AMPK activity is absolutely dependent upon phosphorylation of AMPKαThr-172 in its activation loop by one or more AMPK kinases (AMPKKs). The tumor suppressor kinase, LKB1, is a major AMPKK present in a variety of tissues and cells, but several lines of evidence point to the existence of other AMPKKs. We have employed three cell lines deficient in LKB1 to study AMPK regulation and phosphorylation, HeLa, A549, and murine embryo fibroblasts derived from LKB-/- mice. In HeLa and A549 cells, mannitol, 2-deoxyglucose, and ionomycin, but not…

• HU
  Harvard University
• DC
  Dartmouth College
• UO
  University of Dundee
• NI
  National Institutes of Health
• MR
  Medical Research Council
• NH
  National Health and Medical Research Council