Uhler M D, Chrivia J C, McKnight G S
J Biol Chem. 1986 Nov 25;261(33):15360-3.
We have used a previously characterized mouse cDNA clone for the catalytic (C) subunit of cAMP-dependent protein kinase (Uhler, M. D., Carmichael, D. F., Lee, D. C., Chrivia, J. C., Krebs, E. G., and McKnight, G. S. (1986) Proc. Natl. Acad. Sci. U. S. A. 83, 1300-1304), which we designate C alpha, to isolate cDNA clones coding for a second isoform of the C subunit, C beta. C alpha cDNA clones hybridize to a 2.4-kilobase mRNA on Northern blots whereas C beta cDNA clones detect a 4.3-kilobase mRNA. Nucleotide sequence comparison between C alpha and C beta cDNA clones shows that the C beta cDNA codes for a protein which shows 91% identity with C alpha. Determination of mRNA levels for C beta in various tissues shows that it is most highly expressed in brain although it is detectable in all tissues examined. The presence of two genes coding for the C subunit of cAMP-dependent protein kinase may explain past reports of heterogeneity in C subunit protein preparations.
我们使用了先前鉴定的编码环磷酸腺苷（cAMP）依赖性蛋白激酶催化（C）亚基的小鼠cDNA克隆（乌勒，M.D.，卡迈克尔，D.F.，李，D.C.，克里维亚，J.C.，克雷布斯，E.G.，和麦克奈特，G.S.（1986年）《美国国家科学院院刊》83，1300 - 1304），我们将其命名为Cα，来分离编码C亚基第二种同工型Cβ的cDNA克隆。Cα cDNA克隆在Northern印迹上与2.4千碱基的mRNA杂交，而Cβ cDNA克隆检测到一个4.3千碱基的mRNA。Cα和Cβ cDNA克隆之间的核苷酸序列比较表明，Cβ cDNA编码的蛋白质与Cα有91%的同一性。对各种组织中Cβ的mRNA水平的测定表明，它在脑中表达最高，尽管在所有检测的组织中都可检测到。编码cAMP依赖性蛋白激酶C亚基的两个基因的存在可能解释了过去关于C亚基蛋白质制备中异质性的报道。
