Enhanced expression of multiple protein tyrosine phosphatases in the regenerating mouse liver: isolation of PTP-RL10, a novel cytoplasmic-type phosphatase with sequence homology to cytoskeletal protein 4.1.
Enhanced expression of multiple protein tyrosine phosphatases in the regenerating mouse liver: isolation of PTP-RL10, a novel cytoplasmic-type phosphatase with sequence homology to cytoskeletal protein 4.1.
复制标题
再生小鼠肝脏中多种蛋白酪氨酸磷酸酶的表达增强：PTP-RL10 的分离，这是一种与细胞骨架蛋白 4.1 具有序列同源性的新型细胞质型磷酸酶。
作者：
H. Higashitsuji;S. Arii;M. Furutani;M. Imamura;Y. Kaneko;J. Takenawa;H. Nakayama;J. Fujita
为了阐明蛋白酪氨酸磷酸酶（PTPs）在肝再生中可能发挥的作用，采用基于PCR的克隆方法研究了部分肝切除（PH）后小鼠肝脏中PTPs的表达。115个cDNA克隆的测序鉴定了10个不同的序列，包括MPTP（T细胞PTP）、PTP-1B、PTP-P19、mR-PTP μ、R-PTP α、PTP NE-3（PTP-P1）、R-PTP-κ和人LAR的鼠同源物。剩下的两个序列，PTP-RL 9和PTP-RL 10，编码新的PTP。PTP-RL 10 cDNA含有1176个氨基酸的开放阅读框，无明显的跨膜区。氨基端区域与人红细胞蛋白4.1和细胞骨架蛋白ezrin具有序列同源性。在再生的肝脏中，五种PTP基因mRNA的水平（MPTP、PTP-P19、R-PTP α、LAR同源物和PTP-RL 9）在PH后6 h内升高，24 h降至正常水平，48 ~ 72 h再次升高。PTP-1B和R-PTP-kappa mRNA水平在PH后6 h内达到峰值，随后逐渐下降，而PTP-mR-PTP mu和PTP-RL 10 mRNA表达在PH后48 ~ 72 h达高峰，PH后168 h恢复正常。北方印迹法检测到PTPNE-3在肝组织中无表达。多个PTP在肝再生的复制前和复制后阶段的差异表达表明PTP参与肝细胞生长和分化的调节。
To elucidate the role that protein tyrosine phosphatase (PTPs) may play in liver regeneration, PTPs expressed in the mouse liver after partial hepatectomy (PH) were investigated by a PCR-based cloning method. Sequencing of 115 cDNA clones identified 10 different sequences including MPTP (T cell PTP), PTP-1B, PTP-P19, mR-PTP mu, R-PTP alpha, PTP NE-3 (PTP-P1), R-PTP-kappa and the murine homologue of human LAR. The remaining two sequences, PTP-RL9 and PTP-RL10, encoded novel PTPs. PTP-RL10 cDNA contained an open reading frame of 1176 amino acids with no apparent membrane-spanning region. The amino-terminal region had sequence homology to those of human erythrocyte protein 4.1 and ezrin, cytoskeletal proteins. In the regenerating liver, the levels of five PTP gene mRNAs (MPTP, PTP-P19, R-PTP alpha, LAR homologue, and PTP-RL9) increased within 6 h, decreased to the normal level by 24 h, and increased again at 48 to 72 h after PH. The levels of PTP-1B and R-PTP-kappa mRNAs peaked within 6 h, decreased gradually, and returned to the normal level by 168 h after PH. In contrast, the levels of two PTP mRNAs (mR-PTP mu and PTP-RL10) peaked at 48 to 72 h, and returned to the normal level by 168 h after PH. No expression of PTP NE-3 was detected in the liver by Northern blotting. The differential expression of multiple PTPs during the pre-replicative and post-replicative stages of liver regeneration suggests that PTPs are involved in the regulation of growth and differentiation of liver cells.