Analysis of a novel human protein WDC146 highly expressed in testis : for elucidation of the function during spermatogenesis

1)WDC146是一种新的人类蛋白质，全长146 kDa，在睾丸中高表达。WDC146由三个结构域组成，分别为WD40结构域、胶原样结构域和富含GPR的重复结构域，从N端到C端。2)WDC146在人和小鼠的睾丸中高表达。氨基酸序列同源性高达96%，其中WD40区氨基酸序列完全匹配(100%)。3)WDC146在粗线期精母细胞中有显著表达，并在细胞核和核周定位于细胞内。4)WDC146在精子发生过程中的表达模式的详细分析正在进行中，技术上的困难是睾丸的固定适用于原位杂交。5)WD40结构域被认为是蛋白质相互作用的平台基序。重复进行双杂交筛选，以检测与WDC146相互作用的蛋白，但尚未成功。6)肿瘤-睾丸基因是指睾丸特异基因，也在许多肿瘤和肿瘤细胞系中表达。7)WDC146基因定位于2Q14-21，由22个外显子组成。除约4kb的完整mRNA外，还检测到约1kb的错配嵌合体。8)外显子1上游0.5kb区域存在启动子区域。

1) WDC146 is a novel human protein of 146 kDa which is expressed highly in testis. It is composed of three domains, a WD40 domain, a collagen-like domain and a GPR-rich repeat domain, from N-terminus to C-terminus, respectively.2) WDC146 is highly expressed in testis both in human and mouse. The amino acid sequence showed significant homology between them overall (96%), including complete match (100%) for the region of WD40 domain. Even in Drosophila and yeast, we identified the sequence conserved in part.3) WDC146 showed marked expression in pachytene spermatocytes, and nuclear and perinuclear localization was observed intracellularly.4) The detailed analysis of the expression pattern of WDC146 during spermatogenesis is in progress, with the technical difficulty of fixation of testis applicable for in situ hybrization.5) WD40 domain is known to work as the platform motif as the time of protein-protein interaction. The two-hybrid screening was executed repeatedly to detect interactive protein with WDC146, but not yet succeed.6) Cancer-testis genes are defined as testis-specific genes also expressed in many tumors and tumor cell lines. WDC146 may be classified in them, as tumor cell lines tested all showed moderate expression of WDC146, though some tumors did not.7) The WDC146 gene is mapped at 2q14-21 and consists of 22 exons. Besides the intact mRNA of about 4kb, a chimeric one result from mis-splicing always detected at about 1kb size.8) The promoter region was identified within 0.5kb upstream region of exon 1.