ACROGRANIN, AN ACROSOMAL CYSTEINE-RICH GLYCOPROTEIN, IS THE PRECURSOR OF THE GROWTH-MODULATING PEPTIDES, GRANULINS, AND EPITHELINS, AND IS EXPRESSED IN SOMATIC AS WELL AS MALE GERM-CELLS
ACROGRANIN, AN ACROSOMAL CYSTEINE-RICH GLYCOPROTEIN, IS THE PRECURSOR OF THE GROWTH-MODULATING PEPTIDES, GRANULINS, AND EPITHELINS, AND IS EXPRESSED IN SOMATIC AS WELL AS MALE GERM-CELLS
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DOI：
10.1002/mrd.1080340302
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发表时间：
1993-03-01
影响因子：
2.5
通讯作者：
GERTON, GL
中科院分区：
文献类型：
--
作者：
BABA, T;HOFF, HB;GERTON, GL
精子发生是一个独特的分化系统，涉及细胞重塑和精子特异性细胞器的生物发生。为了研究顶体的生物发生，我们研究了哺乳动物精子发生过程中顶体蛋白的基因表达、生物合成和靶向作用。我们最近纯化并开始表征的顶体标记物是顶粒蛋白，一种最初从豚鼠睾丸中分离的67，000分子量的糖蛋白。这种糖蛋白在粗线期精母细胞中检测到，随后在发育中的精子细胞和精子的顶体中发现。几种组织的免疫印迹和免疫荧光定位在豚鼠睾丸的冷冻切片表明，顶粒蛋白是一种生殖细胞特异性糖蛋白，表达减数分裂和减数分裂后。然而，北方印迹分析表明，顶粒蛋白的mRNA普遍表达在所有豚鼠和小鼠组织检查。此外，豚鼠和小鼠的acrogranins的一级结构，推导出的cDNA序列，揭示了这种糖蛋白是一个富含半胱氨酸的分子，其基序串联重复7次，非常类似于人上皮/颗粒蛋白前体。我们的结论是，豚鼠和小鼠的acrogranins的同源物的人和大鼠上皮/颗粒蛋白肽的前体先前被证明具有生长调节特性。
Spermatogenesis is a unique system of differentiation involving cellular remodeling and the biogenesis of sperm-specific organelles. To study the biogenesis of one such organelle, the acrosome, we have been examining the gene expression, biosynthesis, and targeting of specific acrosomal proteins during mammalian spermatogenesis. An acrosomal marker that we recently purified and began characterizing is acrogranin, a 67,000-molecular-weight glycoprotein originally isolated from guinea pig testes. This glycoprotein is detected in pachytene spermatocytes and is found later in the acrosomes of developing spermatids and sperm. Immunoblotting of several tissues and immunofluorescent localization in frozen sections of guinea pig testes suggested that acrogranin was a germ cell-specific glycoprotein that was expressed meiotically and post-meiotically. However, Northern blot analysis demonstrated that the mRNA for acrogranin was ubiquitously expressed in all guinea pig and mouse tissues examined. Furthermore, the primary structures of guinea pig and mouse acrogranins, deduced from the cDNA sequences, reveal that this glycoprotein is a cysteine-rich molecule with a motif that is tandemly repeated seven times, very similar to that of the human epithelin/granulin precursor. We conclude that guinea pig and mouse acrogranins are homologues of the precursor of the human and rat epithelin/granulin peptides previously demonstrated to have growth-modulating properties.