Kramerova Irina A, Kramerov Andrei A, Fessler John H
Molecular Biology Institute and Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, California 90095, USA.
Dev Dyn. 2003 Apr;226(4):634-42. doi: 10.1002/dvdy.10265.
Papilins are extracellular matrix proteins that share a particular, common order of types of protein domains. They occur widely, from nematodes to man, and can differ in the number of repeats of a given type of domain. Protein variety is increased by differential splicing of pre-mRNA. We report that Drosophila, which has a compact genome, expresses three splice variants of papilin during embryogenesis in developmentally defined patterns. These isoforms have different numbers of Kunitz and IgC2 domains. The papilin isoforms are expressed in specific cell types and contribute to different extracellular matrices in gastrulation folds, early mesoderm, heart formation, basement membranes, and elaboration of the excorporeal peritrophic membrane that lines the gut. This finding indicates an unexpectedly broad spectrum of different pericellular matrices in Drosophila embryos. Such papilin-containing matrices have developmental as well as functional significance, as we previously showed that both suppression of papilin synthesis and ectopic overexpression lethally disrupt organogenesis.
帕皮林蛋白是细胞外基质蛋白，它们具有特定的、常见的蛋白质结构域类型顺序。从线虫到人类，它们广泛存在，并且给定类型结构域的重复次数可能不同。前体信使核糖核酸的可变剪接增加了蛋白质的多样性。我们报告称，具有紧凑基因组的果蝇在胚胎发育过程中以发育定义的模式表达帕皮林蛋白的三种剪接变体。这些异构体的Kunitz和IgC2结构域数量不同。帕皮林蛋白异构体在特定细胞类型中表达，并有助于原肠胚褶、早期中胚层、心脏形成、基底膜以及肠道内衬的体外围食膜的形成过程中形成不同的细胞外基质。这一发现表明果蝇胚胎中不同细胞周围基质的范围出人意料地广泛。正如我们之前所表明的，抑制帕皮林蛋白合成和异位过表达都会致命地破坏器官发生，因此这种含有帕皮林蛋白的基质具有发育和功能意义。
