Nerve growth factor stimulates a protein kinase in PC-12 cells that phosphorylates microtubule-associated protein-2.

摘要: Some of the effects nerve growth factor (NGF) may be mediated by changes in protein phosphorylation. We have identified a kinase from PC-12 cells that catalyzes phosphorylation pig brain microtubule-associated (MAP)-2 vitro. This activity is stimulated 2-4-fold extracts treated with NGF or epidermal (EGF). The partial purification and characterization this MAP indicate it distinct previously described NGF-stimulated kinases. unaffected direct addition to assay heat-stable cAMP-dependent peptide inhibitor, staurosporine, K-252A, slightly heparin inhibited sodium fluoride calcium ions. Treatment increases within 2 min. declines after 10 min, second phase activation observed at 20-30 Comparison its behavior on gel permeation sucrose density gradients indicates molecular mass range 40,000 daltons. specific for ATP as substrate Km 12 microM. Although pathway unknown, stimulation can reversed treatment enzyme alkaline phosphatase, suggesting involves itself. properties hormone sensitivity suggest similar identified, factor-sensitive 3T3-L1 adipocytes.