MOLECULAR SIGNALS FOR TRAFFICKING SURFACTANT PROTEIN B

描述(改编自申请人的摘要)：在本建议书中， 假设1)ProSP-B、中间体和成熟SP-B8的运动 细胞器的特异性促进了对板层小体的连接 PROSP-B处理的分区，以及2)内包含的信号 成熟SP-B侧翼的N-末端和C-末端多肽在 将SP-B运输到板层小体。对特定目标1的研究将 阐明人SP-B的加工步骤，并定位中间体 和切割产物到亚细胞细胞器通过使用 表位特异性抗体和细胞器特异性标记，以及 干扰细胞器转移的药理物质。在目标2中，一个 使用FLAG序列标记的SP-B基因将被开发来追踪 以内源性SP-B为背景的2型细胞重组SP-B 制作。Prosp-B的N-末端和C-末端的关键区域将 改变以检测重组SP-B蛋白的异常运输。 这些研究将在人胎肺外植体上进行， 培养形成大量稳定的2型细胞群，适合于 研究SP-B的加工和贩运。

DESCRIPTION (Adapted from the applicant's abstract): In this proposal, it is hypothesized that 1) movement of proSP-B, intermediates, and mature SP-B8 to the lamellar body is facilitated by organelle-specific compartmentalization of proSP-b processing, and 2) signals contained within the N- and C-terminal peptides flanking mature SP-B are important in trafficking SP-B to the lamellar body. Studies in Specific Aim 1 will clarify the steps in processing of human SP-B, and localize intermediates and cleavage products to subcellular organelles through the use of epitope-specific antibodies and organelle-specific markers, as well as pharmacologic agents that interfere with organelle transfer. In Aim 2, a tagged SP-B cDNA using the FLAG-sequence will be developed to track recombinant SP-B through type 2 cells on a background of endogenous SP-B production. Key regions of the N- and C-terminal peptides of proSP-B will be altered to examine aberrant trafficking of the recombinant SP-B protein. These studies will be carried out in human fetal lung explants which in culture develop a large stable population of type 2 cells suitable for studying processing and trafficking of SP-B.