College of Ocean, Hebei Agriculture University, No. 52, HeBei Street, 066003 Qinhuangdao, Hebei, People's Republic of China.
Mol Biol Rep. 2009 Nov;36(8):2431-7. doi: 10.1007/s11033-009-9474-x. Epub 2009 Feb 27.
The p8 protein is a transcription factor with a basic helix-loop-helix motif and a nuclear localization signal. In the present study, a common sea urchin (Paracentrotus lividus) homolog of p8 cDNA was cloned, sequenced and characterized. The full-length p8 cDNA consists of 896 bp and encodes 71 amino acids with a molecular mass of 8.238 kD. Homology alignments found that several phosphorylation sites and the most negative (Asp and Glu)/positive (Arg) propensities charged residues were well conserved between P. lividus and other species. Analysis by RT-PCR showed that there was no obvious difference in the patterns of expression during embryogenesis from unfertilization egg up to the pluteus stage, but p8 mRNA expression levels varied among tested adult tissues suggesting that p8 has a key function in embryogenesis but non-vital function under physiological conditions. Evolution relationships between P. lividus p8 and other species p8 homologs revealed in the phylogenetic tree were in agreement with the concept of traditional taxonomy.
p8 蛋白是一种具有碱性螺旋-环-螺旋结构基序和核定位信号的转录因子。本研究克隆、测序并表征了一种常见的海胆（Paracentrotus lividus）p8 cDNA 同源物。全长 p8 cDNA 由 896bp 组成，编码 71 个氨基酸，分子量为 8.238kD。同源性比对发现，p8 蛋白在氨基酸序列上高度保守，具有多个磷酸化位点和最负（天冬氨酸和谷氨酸）/正（精氨酸）电荷倾向的残基。通过 RT-PCR 分析发现，p8 在从受精卵到幼体阶段的胚胎发生过程中的表达模式没有明显差异，但 p8mRNA 在测试的成年组织中的表达水平存在差异，这表明 p8 在胚胎发生中具有关键作用，但在生理条件下非必需。系统进化树中显示的 p. lividus p8 与其他物种 p8 同源物之间的进化关系与传统分类学的概念一致。
