GENE EXPRESSION DURING THE DUCT CELL DIFFERENTIATION IN SALIVARY GLANDS

1)大鼠舌下腺表达的新蛋白：克隆了一个主要在大鼠舌下腺表达的新基因，命名为503个氨基酸的蛋白SLAMP(舌下腺泡膜蛋白)。SLAMP与动物L凝集素家族中的人ERGIC-53类蛋白有63%的同源性。SLAMP基因和蛋白主要表达于舌下腺粘液腺泡细胞。在超微结构上，SLAMP定位于内质网高尔基体中间隔(ERGIC)，提示SLAMP参与糖蛋白的早期分泌途径。2)制备时间短、成本低的大鼠多克隆抗体的新方法：制备抗体通常需要较长的时间。我们开发了一种在不到一个月的时间内制备多克隆抗体的新方法，该方法是在制备重组寡肽作为抗原的基础上，然后免疫大鼠。利用这种方法，我们制备了ERGIC-53的抗血清，并证实了它在ERGIC中的定位。3)一种新的小鼠下颌下雄激素抑制蛋白：我们鉴定了一个来源于雌性小鼠下颌下腺(SMG)的cDNA克隆。该克隆的蛋白产物含有一个165个氨基酸的蛋白，含有一个可能的信号序列，命名为下颌下雄激素抑制蛋白(SMARP)。在小鼠中，SMARP基因仅在SMG和眼眶外泪腺表达。SMG中Smarp基因的表达水平女性是男性的36倍，男性是女性LG的28倍。此外，在给雌性或去势雄性注射睾酮后，SMG组的睾丸激素水平降低，而LG组的水平升高。SMG和泪腺中SMAP的mRNA和蛋白主要定位于腺泡细胞。这些结果表明，Smarp是一种分泌型蛋白，其在SMG中的表达受雄激素的负调控，在LG中受雄激素的正调控。

1)A novel protein expressed in rat sublingual gland : We cloned a novel rat gene expressed primarily in the sublingual gland and named the predicted 503 amino-acid protein SLAMP (sublingual acinar membrane protein). SLAMP had 63% homology with human ERGIC-53-like protein, a member of the family of animal L-type lectins. SLAMP mRNA and protein were expressed predominantly in the mucous acinar cells of sublingual gland. Ultrastructurally, SLAMP was localized to the ER-Golgi intermediate compartment (ERGIC), suggesting that SLAMP functions in the early secretory pathway of glycoproteins. 2)A new method of producing rat polyclonal antibodies with shorter time and lower cost: Producing antibodies usually takes a long time. We developed a new method of producing polyclonal antibodies in less than a month, based on preparation of the recombinant oligopeptides as antigen followed by immunization of rats. Using this method, we produced antisera against ERGIC-53 and confirmed its localization in the ERGIC. 3)A novel submandibular androgen-repressed protein of the mouse: We characterized a cDNA clone derived from the female mouse submandibular gland (SMG). The protein product of this clone had a 165-amino acid protein with a putative signal sequence and was named submandibular androgen-repressed protein (SMARP). In the mouse SMARP mRNA was expressed only in the SMG and exorbital lacrimal gland (LG). The level of SMARP mRNA was 36 times higher in female than male SMG, whereas it was 28 times higher in male than female LG. Furthermore, it was reduced in SMG but increased in LG after administration of testosterone to females or castrated males. SMARP mRNA and protein were predominantly localized in acinar cells in both SMG and lacrimal gland. These results suggested that SMARP is a secretory protein whose expression is regulated by androgens negatively in the SMG and positively in the LG.