Phosphorylation of MYPT1 by protein kinase C attenuates interaction with PP1 catalytic subunit and the 20 kDa light chain of myosin

FEBS Letters

Hartshorne, David J.²  Walsh, Michael P.¹  Kiss, Enikö³  Tóth, Attila³  Gergely, Pál³  Erdödi, Ferenc³ 

[1] Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alta., Canada T2N 4N1;Muscle Biology Group, University of Arizona, Tucson, AZ 85721, USA;Department of Medical Chemistry, Medical and Health Science Center, University of Debrecen, Bem tér 18/B, H-4012 Debrecen, Hungary

关键词: Myosin phosphatase;    Protein phosphatase 1;    Myosin phosphatase target subunit 1;    Protein kinase C;    Ankyrin repeat;    MC-LR;    microcystin-LR;    MLC20;    20 kDa light chain of smooth muscle myosin;    MLCK;    myosin light chain kinase;    MP;    myosin phosphatase;    MYPT1;    myosin phosphatase target subunit 1;    PBS;    phosphate-buffered saline;    PKA;    cAMP-dependent protein kinase;    P-MLC20;    phosphorylated form of MLC20;    PP1;    type 1 protein phosphatase;    PP1c;    catalytic subunit of type 1 protein phosphatase;    rPP1c;    recombinant PP1c (δ isoform) expressed as a hexahistidine-tagged protein in Escherichia coli;    SPR;    surface plasmon resonance;    PKC;    protein kinase C;   

DOI  :  10.1016/S0014-5793(00)02138-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The effect of phosphorylation in the N-terminal region of myosin phosphatase target subunit 1 (MYPT1) on the interactions with protein phosphatase 1 catalytic subunit (PP1c) and with phosphorylated 20 kDa myosin light chain (P-MLC20) was studied. Protein kinase C (PKC) phosphorylated threonine-34 (1 mol/mol), the residue preceding the consensus PP1c-binding motif (³⁵KVKF³⁸) in MYPT1^1–38, but this did not affect binding of the peptide to PP1c. PKC incorporated 2 mol P_i into MYPT1^1–296 suggesting a second site of phosphorylation within the ankyrin repeats (residues 40–296). This phosphorylation diminished the stimulatory effect of MYPT1^1–296 on the P-MLC20 phosphatase activity of PP1c. Binding of PP1c or P-MLC20 to phosphorylated MYPT1^1–296 was also attenuated. It is concluded that phosphorylation of MYPT1 by PKC may therefore result in altered dephosphorylation of myosin.

【 授权许可】

Unknown