Identification of a cryptic protein kinase CK2 phosphorylation site in human complement protease C1r, and its use to probe intramolecular interaction

FEBS Letters

Hudry-Clergeon, Gilbert³  Pétillot, Yves¹  Pelloux, Sophie³  Thielens, Nicole M.³  Arlaud, Gérard J.³  Filhol, Odile² 

[1] Laboratoire de Spectrométrie de Masse des Protéines, Institut de Biologie Structurale Jean-Pierre Ebel (CEA/CNRS), 41 Avenue des Martyrs, 38027 Grenoble Cedex 1, France;Laboratoire de Biochimie des Régulations Cellulaires Endocrines, Département de Biologie Moléculaire et Structurale, CEA-Grenoble, 17 Avenue des Martyrs, 38054 Grenoble Cedex 9, France;Laboratoire d'Enzymologie Moléculaire, Institut de Biologie Structurale Jean-Pierre Ebel (CEA/CNRS), 41 Avenue des Martyrs, 38027 Grenoble Cedex 1, France

关键词: Complement;    C1r;    Protein phosphorylation;    Protein kinase CK2;    Activated complement components are indicated by an overbar;    e.g. Cr;    CaMK-II;    calcium/calmodulin-dependent kinase II;    CK2;    protein kinase CK2;    DFP;    diisopropyl phosphorofluoridate;    PNGase-F;    peptide N-glycosidase F;    pNpGB;    p-nitrophenyl-p′-guanidinobenzoate;    SDS-PAGE;    sodium dodecyl sulfate-polyacrylamide gel electrophoresis;   

DOI  :  10.1016/0014-5793(96)00403-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Treatment of human Cr by CK2 resulted in the incorporation of [³²P]phosphate into the N-terminal α region of its non-catalytic A chain. Fragmentation of ³²P-labelled Cr followed by N-terminal sequence and mass spectrometry analyses allowed identification of Ser₁₈₉ as the phosphorylation site. Accessibility of Ser₁₈₉ was low in intact C1r, due in part to the presence of one of the oligosaccharides borne by the α region, further reduced in the presence of calcium, and abolished when C1r was incorporated into the C1s-C1r-C1r-C1s treatment or the C1 complex. In contrast, phosphorylation was enhanced in the isolated α fragment and insensitive to calcium. Taken together, these data provide support for the occurrence of a Ca²⁺-dependent interaction between the α region and the remainder of the C1r molecule.

【 授权许可】

Unknown