Összesen 3 találat.


001-es BibID:BIBFORM028725
Első szerző:Murányi Andrea (biokémikus)
Cím:Phosphorylation of the myosin phosphatase target subunit by integrin-linked kinase / Andrea Murányi, Justin A. MacDonald, Jing Ti Deng, David P. Wilson, Timothy A. J. Haystead, Michael P. Walsh, Ferenc Erdődi, Enikő Kiss, Yue Wu, David J. Hartshorne
Megjegyzések:A mechanism proposed for regulation of myosin phosphatase (MP) activity is phosphorylation of the myosin phosphatase target subunit (MYPT1). Integrin-linked kinase (ILK) is associated with the contractile machinery and can phosphorylate myosin at the myosin light-chain kinase sites. The possibility that ILK may also phosphorylate and regulate MP was investigated. ILK was associated with the MP holoenzyme, shown by Western blots and in-gel kinase assays. MYPT1 was phosphorylated by ILK and phosphorylation sites in the N- and C-terminal fragments of MYPT1 were detected. From sequence analyses, three sites were identified: a primary site at Thr(709), and two other sites at Thr(695) and Thr(495). One of the sites for cAMP-dependent protein kinase (PKA) was Ser(694). Assays with the catalytic subunit of type 1 phosphatase indicated that only the C-terminal fragment of MYPT1 phosphorylated by zipper-interacting protein kinase, and ILK inhibited activity. The phosphorylated N-terminal fragment activated phosphatase activity and phosphorylation by PKA was without effect. Using full-length MYPT1 constructs phosphorylated by various kinases it was shown that Rho kinase gave marked inhibition; ILK produced an intermediate level of inhibition, which was considerably reduced for the Thr(695)-->Ala mutant; and PKA had no effect. In summary, phosphorylation of the various sites indicated that Thr(695) was the major inhibitory site, Thr(709) had only a slight inhibitory effect and Ser(694) had no effect. The findings that ILK phosphorylated both MYPT1 and myosin and the association of ILK with MP suggest that ILK may influence cytoskeletal structure or function.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
külföldön készült közlemény
Megjelenés:Biochemical Journal. - 366 (2002), p. 211-216. -
További szerzők:MacDonald, Justin A. Deng, Jing Ti Wilson, David P. Haystead, Timothy A. J. Walsh, Michael P. Kiss Enikő Wu, Yue Hartshorne, David J. Erdődi Ferenc (1953-) (biokémikus)
Internet cím:Szerző által megadott URL
Intézményi repozitóriumban (DEA) tárolt változat


001-es BibID:BIBFORM028723
Első szerző:Wu, Yue
Cím:Myosin phosphatase and myosin phosphorylation in differentiating C2C12 cells / Yue Wu, Ferenc Erdődi, Andrea Murányi, Kevin D. Nullmeyer, Ronald M. Lynch, David J. Hartshorne
Megjegyzések:C2C12 cells offer a useful model to study the differentiation of non-muscle cells to skeletal muscle cells. Myosin phosphorylation and changes in related enzymes, with an emphasis on myosin phosphatase (MP) were analyzed over the first 6 days of C2C12 differentiation. There was a transition from myosin phosphatase target subunit 1 (MYPT1), predominant in the non-muscle cells to increased expression of MYPT2. Levels of MYPT1/2 were estimated, and both isoforms were higher in non- or partially differentiated cells compared to the concentrations in the differentiated isolated myotubes from day 6. A similar profile of expression was estimated for the type 1 protein phosphatase catalytic subunit, delta isoform (PP1c delta). Phosphatase activities, using phosphorylated smooth and skeletal muscle myosins, were estimated for total cell lysates and isolated myotubes. In general, smooth muscle myosin was the preferred substrate. Although the expression of MYPT1/2 and PP1c delta was considerably reduced in isolated myotubes the phosphatase activities were not reduced to corresponding levels. Most of the MP activity was due to PP1c, as indicated by okadaic acid. In spite of relatively high expression of MYPT1/2 and PP1c delta, marked phosphorylation of non-muscle myosin (over 50% of total myosin) was observed at day 2 (onset of expression of muscle-specific proteins) and both mono- and diphosphorylated light chains were observed. Partial inhibition of MLCK by 1-(5-chloronaphthalene-1-sulphonyl)-1H-hexahydro-1,4-diazepine HCl (ML-9) or by a construct designed from the autoinhibitory domain of MLCK, resulted in an increase in small myotubes (3-5 nuclei) after 3 days of differentiation and a decrease in larger myotubes (compared to control). The effect of ML-9 was not due to a reduction in intracellular Ca2+ levels. These results suggest that phosphorylation of non-muscle myosin is important in growth of myotubes, either in the fusion process to form larger myotubes or indirectly, by its role in sarcomere organization.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
külföldön készült közlemény
Megjelenés:Journal of Muscle Research and Cell Motility. - 24 : 8 (2003), p. 499-511. -
További szerzők:Murányi Andrea (1966-) (biokémikus) Nullmeyer, Kevin D. Lynch, Ronald M. Hartshorne, David J. Erdődi Ferenc (1953-) (biokémikus)
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat


001-es BibID:BIBFORM003572
Első szerző:Wu, Yue
Cím:Localization of myosin phosphatase target subunit and its mutants / Wu Y., Murányi A., Erdődi F., Hartshorne D. J.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
smooth muscle
nuclear localization
transient transfection
Megjelenés:Journal of Muscle Research and Cell Motility. - 26 : 2-3 (2005), p. 123-134. -
További szerzők:Murányi Andrea (1966-) (biokémikus) Hartshorne, David J. Erdődi Ferenc (1953-) (biokémikus)
Internet cím:elektronikus változat
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