Martelo O J, Toro E F, Hirsch J
J Lab Clin Med. 1976 Jan;87(1):83-8.
Renal erythropoietic factor (REF) serves as a substrate for a cyclic nucleotide-dependent protein kinase. The phosphorylation of REF is associated with increased erythropoietic activity. Conversely, REF isolated from hypoxic rats is a poor phosphate acceptor. These findings and the presence of a positive correlation between erythropoietin levels and urinary excretion of adenosine 3',5' monophosphate (cyclic-AMP) in anemic individuals suggest that the cyclic-AMP-protein kinase system plays an important role in the activation of REF.
肾红细胞生成因子（REF）作为一种环核苷酸依赖性蛋白激酶的底物。REF的磷酸化与红细胞生成活性增加有关。相反，从缺氧大鼠中分离出的REF是一种较差的磷酸受体。这些发现以及贫血个体中促红细胞生成素水平与尿中3',5'-单磷酸腺苷（环磷酸腺苷）排泄之间存在正相关，表明环磷酸腺苷-蛋白激酶系统在REF的激活中起重要作用。
