Wang Z Q, Akmal K M, Kim K H
Department of Genetics and Cell Biology, Washington State University, Pullman 99164.
Biol Reprod. 1994 Nov;51(5):1022-30. doi: 10.1095/biolreprod51.5.1022.
An mRNA with a substantial similarity to the rat p62 mRNA that encodes a nucleoporin was cloned from the rat testis. A probe derived from a unique sequence in the nucleoporin-related (NPR) cDNA revealed a novel mRNA of 1.3 kb, different from the 2.7-kb transcript attributed to the p62 gene. This 1.3-kb transcript was not detected in Sertoli cells; it was found primarily in the haploid germ cells of the adult testis. The DNA sequencing revealed that the central region of the NPR cDNA sequence was identical to the 3' portion of the p62 cDNA containing heptad repeat sequences. However, the 5' region and the extreme 3' region of the NPR cDNA sequence were different from the p62 cDNA. Interestingly, the extreme 3' untranslated region (UTR) contained a 212-bp inverted repeat of a sequence located in the middle of the NPR cDNA that is identical to the p62 sequence. The inverted repeats of the NPR sequence could potentially hybridize, leading to the formation of circular transcripts. Using antibodies specific for the C-terminal regions of p62, a 26-kDa protein was detected from NPR cDNA hybrid-arrested translational products, and a 28-kDa protein was detected from the testis germ cell extracts but not from Sertoli cell extracts.
从大鼠睾丸中克隆出一种与编码核孔蛋白的大鼠p62 mRNA具有高度相似性的mRNA。源自核孔蛋白相关（NPR）cDNA独特序列的探针揭示了一种1.3 kb的新mRNA，不同于归因于p62基因的2.7 kb转录本。在支持细胞中未检测到这种1.3 kb的转录本；它主要存在于成年睾丸的单倍体生殖细胞中。DNA测序显示，NPR cDNA序列的中心区域与包含七肽重复序列的p62 cDNA的3'部分相同。然而，NPR cDNA序列的5'区域和最末端的3'区域与p62 cDNA不同。有趣的是，最末端的3'非翻译区（UTR）包含一个212 bp的反向重复序列，该序列位于NPR cDNA中间，与p62序列相同。NPR序列的反向重复可能会发生杂交，导致形成环状转录本。使用针对p62 C末端区域的特异性抗体，从NPR cDNA杂交捕获的翻译产物中检测到一种26 kDa的蛋白质，从睾丸生殖细胞提取物中检测到一种28 kDa的蛋白质，但在支持细胞提取物中未检测到。
