Identification of novel myosin heavy chain kinases in aorta smooth muscle and significance of phosphorylation of aorta myosin heavy chain
| Project/Area Number |
06455001
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
広領域
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| Research Institution | Hokkaido University |
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Principal Investigator |
MORITA Fumi Graduate School of Science, Hokkaido University, Professor, 大学院理学研究科, 教授 (80000818)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥6,800,000 (Direct Cost: ¥6,800,000)
Fiscal Year 1995: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1994: ¥4,400,000 (Direct Cost: ¥4,400,000)
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| Keywords | aorta smooth muscle / casein kinase II / myosin heavy chain / phosphorylation / protein kinase / タンパク質キナーゼ / タンパク質のりん酸化 / カゼインキナーゼ / 大動脈平滑筋 / ミオシン / りん酸化 |
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| Research Abstract |
In a porcine aorta extract, we observed two protein kinase activities which specifically phosphorylate the 204-kDa heavy chain isoform of aorta myosin in the absence of conventional kinase activators. We referred to these two protein kinases, eluted at 0.15 and 0.2 M KCl from a DEAE-column, as myosin kinases I (MKI) and II (MKII) , respectively. The phosphorylation site for MKI was determined using a purified phosphopeptide derived from porcine aorta myosin phosphorylated with MKI.By comparison with the deduced amino acid sequence for smooth muscle myosins, the site corresponded to a Ser located at 3 amino acids upstream from a Pro, the putative end of the alpha-helical segment of the 204-kDa heavy chain tail. A homologous Ser is only present in smooth muscle myosins, i. e. not in nonmuscle myosins. MKI was purified 130-fold, but not separated from a kinase activity phosphorylating Ser1 or Ser2 in the 20-kDa regulatory light chain of aorta myosin. In contrast, MKII was purified to near homogeneity. MKII phosphorylated the porcine aorta myosin heavy chain at a Ser 19 amino acids downstream from the MKI site. The amino acid sequence around the Ser shared a consensus sequence of the phosphorylation site for casein kinase II and was homologous to that reported for bovine aorta myosin (Kelley, C.A., and Adelstein, R.S.(1990) J.Biol.Chem.265,17876-17882) . MKII was identified as a multifunctional protein kinase, casein kinase II.
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Report
(3 results)
Research Products
(3 results)
