Subunit‐specific phosphorylation of pyruvate kinase in medullary thyroid carcinomas of the rat

FEBS Letters

Oskam, Ralph¹  van der Heijden, Margreet C.M.¹  Staal, Gerard E.J.¹  Rijksen, Gert¹ 

[1] University Hospital Utrecht, Department of Hematology, Laboratory of Medical Enzymology, PO Box 16250, 3500 CG Utrecht, The Netherlands

关键词: Pyruvate kinase;    Isoenzyme;    Purification;    Phosphorylation;    (Rat medullary thyroid carcinoma;    Tumor);    AMTC;    anaplastic (undifferentiated) medullary thyroid carcinoma;    DMTC;    differentiated medullary thyroid carcinoma;    FDP;    fructose-1;    6-bisphosphate;   

DOI  :  10.1016/0014-5793(88)81357-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Pyruvate kinase from anaplastic medullary thyroid carcinomas contains predominantly K-type subunits, whereas pyruvate kinase from differentiated medullary thyroid carcinomas consist of M- and K-type subunits in about equal proportion. In order to analyse the incorporation of phosphate in the respective isozymes after endogenous phosphorylation of cytosolic extracts with [³²P]ATP, homotetrameric isozymes as well as heterotetrameric hybrids of differentiated0 tumors were resolved by affinity chromatography on Blue-Sepharose CL-6B and, if necessary, further purified by immunoprecipitation. SDS-polyacrylamide gel electrophoresis of purified isozymes and subsequent autoradiography showed the incorporation of phosphate in the K₄-type isozymes, but not in the other isozymes. The phosphorylation appeared to be cAMP-independent and occurred on a serine residue.

【 授权许可】

Unknown