Dickinson D P, Thiesse M
University of Texas, Houston Health Science Center, Department of Basic Sciences 77225, USA.
Curr Eye Res. 1996 Apr;15(4):377-86. doi: 10.3109/02713689608995828.
An abundant 1.05 kb human lacrimal gland mRNA has been characterized by cDNA cloning. It encodes a predicted 180 residue, 20546 Da secreted protein, with a charge of +11 at ph 7 and 24.5% proline, designated as Basic Proline-rich Lacrimal Protein (BPLP), Southern blot analysis is consistent with a single BPLP gene. BPLP lacks any distinct repetitive structure, and is unrelated to the salivary proline-rich protein super-family. The pre-proprotein shows modest overall similarity to a superfamily comprising human PRPb, the mouse MSG proteins, and rat VCS-alpha 1, VCS-beta 1 and submandibular apomucin. BPLP also contains a domain with similarity to the Zp2 protein domain found in several otherwise unrelated proteins. Northern blot analysis indicated that the BPLP gene is also expressed at modest levels in the human submandibular gland, and in situ hybridization demonstrated expression of BPLP in the secretory endpieces of the human lacrimal gland. The BPLP cDNA clone defines a new human tear protein, and should provide a useful phenotypic marker of differentiation in in vitro studies of lacrimal gland function.
通过cDNA克隆对一个丰富的1.05 kb人泪腺mRNA进行了表征。它编码一种预测的含180个残基、20546 Da的分泌蛋白，在pH 7时带 +11电荷，脯氨酸含量为24.5%，命名为富含碱性脯氨酸的泪腺蛋白（BPLP）。Southern印迹分析表明存在单个BPLP基因。BPLP缺乏任何明显的重复结构，且与富含脯氨酸的唾液蛋白超家族无关。前原蛋白与一个超家族整体相似度较低，该超家族包括人PRPb、小鼠MSG蛋白以及大鼠VCS-α1、VCS-β1和下颌下腺脱辅基粘蛋白。BPLP还包含一个与在其他一些不相关蛋白中发现的Zp2蛋白结构域相似的结构域。Northern印迹分析表明BPLP基因在人下颌下腺中也有适度表达，原位杂交显示BPLP在人泪腺的分泌末端表达。BPLP cDNA克隆定义了一种新的人泪液蛋白，在泪腺功能的体外研究中应可作为一种有用的分化表型标记。
