Rapiejko P J, Watkins D C, Ros M, Malbon C C
Department of Pharmacological Sciences, State University of New York, Stony Brook 11794-8651.
Biochim Biophys Acta. 1990 May 2;1052(2):348-50. doi: 10.1016/0167-4889(90)90233-4.
The steady-state levels of mRNAs for the G-proteins Gi alpha 2, Go alpha, and the G beta-subunits common to each were established in rat adipose, heart and liver. Uniformly-radiolabeled, single-stranded antisense probes were constructed from cDNAs or assembled from oligonucleotides. Direct comparison of the steady-state levels of the G-protein mRNAs was performed under identical assay conditions, and on a molar basis. In adipose, liver and heart, Gs alpha mRNA was more abundant than mRNA for Go alpha, Gi alpha, and G beta. In adipose tissue, mRNA levels were as follows: 19.4, 7.6, 7.0, and 2.3 amol mRNA per micrograms total cellular RNA for Gs alpha, G beta, Gi alpha 2, and Go alpha, respectively. In heart Gs alpha mRNA was less abundant than in adipose, but the relative trend among the G-protein subunits was the same. In liver, G beta mRNA was more abundant than either Go alpha or Gi alpha 2. Go alpha mRNA levels ranged from 1.2 to 2.3 amol/micrograms total RNA in liver and adipose, respectively. The present work demonstrates the many advantages of this strategy when applied to the study of a family of homologous, low-abundance proteins and establishes for the first time the molar levels of Gi alpha 2, Gs alpha, Go alpha, and G beta-subunit mRNAs in several mammalian tissues.
在大鼠脂肪组织、心脏和肝脏中测定了G蛋白Giα2、Goα以及它们共有的Gβ亚基的mRNA稳态水平。用cDNA构建或由寡核苷酸组装成均匀放射性标记的单链反义探针。在相同的测定条件下，以摩尔为基础直接比较G蛋白mRNA的稳态水平。在脂肪组织、肝脏和心脏中，GsαmRNA比Goα、Giα和Gβ的mRNA更丰富。在脂肪组织中，mRNA水平如下：Gsα、Gβ、Giα2和Goα的mRNA水平分别为每微克总细胞RNA 19.4、7.6、7.0和2.3 amol。在心脏中，GsαmRNA比在脂肪组织中少，但G蛋白亚基之间的相对趋势是相同的。在肝脏中，GβmRNA比Goα或Giα2更丰富。GoαmRNA水平在肝脏和脂肪组织中分别为每微克总RNA 1.2至2.3 amol。本研究证明了该策略应用于研究同源低丰度蛋白家族时的诸多优点，并首次确定了几种哺乳动物组织中Giα2、Gsα、Goα和Gβ亚基mRNA的摩尔水平。
