Miura I, Nakajima T, Ohtani H, Kashiwagi A, Nakamura M
Laboratory for Amphibian Biology, Faculty of Science, Hiroshima University, Japan.
Zoolog Sci. 1997 Oct;14(5):771-5. doi: 10.2108/zsj.14.771.
14-3-3 proteins constitute a family of well-conserved eukaryotic proteins that possess diverse biochemical activities such as regulation of gene transcription, cell proliferation and activation of protein kinase C. At least 7 subtypes (alpha to theta) of 14-3-3 protein are known, but the zeta subtype of this protein has been cloned only in mammals. We cloned the zeta subtype of 14-3-3 protein (14-3-3 zeta) from the frog, Rana rugosa. The sequence encoded 245 amino acids that share 92% identity with rat and bovine 14-3-3 zeta s, and 92% with human phospholipase A2 (PLA2; 14-3-3 zeta). Northern blot analysis revealed a single band of about 1.8 kb in tadpoles at stage 25. The 14-3-3 zeta mRNA level was high in the brain, lung, spleen and kidney, and low in the heart and testis, as opposed to the mRNA level, which was only faintly detected in the liver, pancreas, ovary and muscle. Furthermore, high similarity in the 3'-untranslated region (3'-UTR) was observed between frog and human 14-3-3 zeta cDNA. The results suggest that 14-3-3 zeta is highly conserved throughout eukaryotic evolution, and that the homologous sequence in the 3'-UTR of 14-3-3 zeta cDNA may be conserved in frogs and humans.
14-3-3蛋白构成了一类高度保守的真核生物蛋白家族，它们具有多种生化活性，如基因转录调控、细胞增殖以及蛋白激酶C的激活。已知14-3-3蛋白至少有7种亚型（α到θ），但该蛋白的ζ亚型仅在哺乳动物中被克隆出来。我们从皱皮蛙中克隆了14-3-3蛋白的ζ亚型（14-3-3 ζ）。该序列编码245个氨基酸，与大鼠和牛的14-3-3 ζ有92%的同一性，与人类磷脂酶A2（PLA2；14-3-3 ζ）也有92%的同一性。Northern印迹分析显示，在第25阶段的蝌蚪中有一条约1.8 kb的单带。14-3-3 ζ mRNA水平在脑、肺、脾和肾中较高，在心脏和睾丸中较低，与在肝脏、胰腺、卵巢和肌肉中仅微弱检测到的mRNA水平相反。此外，在青蛙和人类14-3-3 ζ cDNA的3'-非翻译区（3'-UTR）之间观察到高度相似性。结果表明，14-3-3 ζ在整个真核生物进化过程中高度保守，并且14-3-3 ζ cDNA的3'-UTR中的同源序列在青蛙和人类中可能是保守的。
