ssp160 and Chironomus-Secretory Protein Assembly

蠓（Chironomus）的水生幼虫产生丝状纤维，这种纤维是由幼虫唾液腺合成的分泌蛋白的复合聚合物。当这些蛋白质通过唾液管离开腺体时，它们是如何组装成不溶于水的纤维的尚不清楚。土耳螯虾唾液腺的特殊叶由四个细胞组成，这些细胞合成一种独特的分泌蛋白ssp160。特殊叶与唾液管的接近表明ssp160可能以某种方式参与了分泌蛋白通过唾液管离开腺体时组装和加工成超分子纤维的过程。本建议的目标是学习：1)通过克隆和测序其cDNA确定ssp160的初级结构，2)通过测量体内转录率和mRNA和蛋白质的稳态水平确定其细胞特异性合成的调节水平，3)开始解剖其参与Chironomid分泌蛋白的体外拆卸和重组。这个项目将增强我们对一种独特的生物材料——Chironomid silk的组成、组装和加工的理解。此外，所获得的信息将适用于新型肽基生物分子材料的设计。

Aquatic larvae of the midge, Chironomus, produce silk-like fibers which are composite polymers of secretory proteins synthesized by the larval salivary glands. How these proteins assemble into water-insoluble fibers as they exit the gland through the salivary duct is not known. The special lobe of Chironomus thummi salivary glands consists of four cells which synthesize a unique secretory protein, ssp160. The proximity of the special lobe to the salivary duct implies that ssp160 may somehow be involved in the assembly and processing of secretory proteins into supramolecular fibers as they exit the gland via the duct. The objectives of this proposal are to learn: 1) the primary structure of ssp160 by cloning and sequencing its cDNA, 2) determine the level at which its cell- specific synthesis is regulated by measuring in vivo rates of transcription and steady-state levels of mRNA and protein, and 3) begin to dissect its involvement in Chironomid secretory protein disassembly and reassembly in vitro. %%% This project will enhance our understanding of the composition, assembly and processing of a unique biomaterial, Chironomid silk. Furthermore, the information gained will be applicable to the design of novel peptide-based biomolecular materials.