Harris C A, Andryuk P J, Cline S W, Mathew S, Siekierka J J, Goldstein G
Immunobiology Research Institute, Annandale, New Jersey 08801, USA.
Genomics. 1995 Jul 20;28(2):198-205. doi: 10.1006/geno.1995.1131.
Thymopoietins (TMPOs, previously abbreviated TPs) alpha (75 kDa), beta (51 kDa), and gamma (39 kDa) are related nuclear proteins expressed in many or all tissues. TMPO alpha is present diffusely throughout the nucleus, while TMPOs beta and gamma are localized to the nuclear membrane. Here we report the cloning and analysis of a single TMPO gene encoding TMPOs alpha, beta, and gamma, which are produced by alternative mRNA splicing, as previously inferred from cDNA sequences. The eight exons of the TMPO gene are spread over approximately 35 kb. Exon 4, which is spliced into TMPO alpha mRNA, contains sequences that encode a putative basic nuclear localization motif. Exon 8, which is spliced into TMPO beta and gamma mRNAs, encodes a hydrophobic putative membrane-spanning domain that is thought to target TMPOs beta and gamma to the nuclear membrane. TMPO beta appears to be the human homologue of the recently described rat protein LAP2 (lamina-associated polypeptide 2), which is thought to play an important role in the regulation of nuclear architecture by binding lamin B1 and chromosomes in a manner regulated by phosphorylation during mitosis (K. Furukawa and L. Gerace, La Jolla, pers. comm., 22 Nov. 1994). The human TMPO gene maps to chromosome band 12q22.
胸腺生成素（TMPOs，以前缩写为TPs）α（75 kDa）、β（51 kDa）和γ（39 kDa）是在许多或所有组织中表达的相关核蛋白。TMPOα广泛分布于整个细胞核中，而TMPOsβ和γ则定位于核膜。在此，我们报告了一个编码TMPOsα、β和γ的单一TMPO基因的克隆和分析，这些蛋白是由选择性mRNA剪接产生的，正如先前从cDNA序列推断的那样。TMPO基因的八个外显子分布在约35 kb的区域。剪接到TMPOα mRNA中的外显子4包含编码一个假定的碱性核定位基序的序列。剪接到TMPOβ和γ mRNA中的外显子8编码一个疏水的假定跨膜结构域，该结构域被认为将TMPOsβ和γ靶向到核膜。TMPOβ似乎是最近描述的大鼠蛋白LAP2（核纤层相关多肽2）的人类同源物，据认为它在有丝分裂期间通过以磷酸化调节的方式结合核纤层蛋白B1和染色体来调节核结构中起重要作用（K. Furukawa和L. Gerace，拉霍亚，个人通信，1994年11月22日）。人类TMPO基因定位于染色体12q22带。
