Doctor J S, Jackson P D, Rashka K E, Visalli M, Hoffmann F M
McArdle Laboratory for Cancer Research, University of Wisconsin, Madison 53706.
Dev Biol. 1992 Jun;151(2):491-505. doi: 10.1016/0012-1606(92)90188-m.
More than 20 members of the transforming growth factor-beta (TGF-beta) superfamily of growth and differentiation factors have been implicated in development. One member of the TGF-beta family has been previously reported from Drosophila, the decapentaplegic (dpp) gene which is involved in embryonic dorsal/ventral polarity, embryonic gut formation, and imaginal disk development. Using PCR methods, we have identified a second Drosophila gene in the TGF-beta family. It encodes a protein product that is more similar to the TGF-beta-related human bone morphogenetic proteins (BMPs) 5, 6, and 7 than it is to the Drosophila dpp gene product. Because of its localization on the polytene chromosome map, we refer to this gene as 60A. Expression of a 60A cDNA in Drosophila S2 cells was used to determine that 60A encodes a preproprotein that is processed to yield secreted amino- and carboxy-terminal polypeptides. The carboxy-terminal peptides are recovered as disulfide-linked homodimers. The 60A transcripts and protein are first detected at the onset of gastrulation, primarily in the mesoderm of the extending germ band. As the germ band retracts, and throughout later stages of embryonic development, the 60A transcript and protein are most readily detected in cells of the developing foregut and hindgut.
超过20种生长和分化因子的转化生长因子-β（TGF-β）超家族成员与发育有关。之前已从果蝇中报道了TGF-β家族的一个成员，即参与胚胎背/腹极性、胚胎肠道形成和成虫盘发育的截瘫（dpp）基因。我们使用PCR方法在TGF-β家族中鉴定出了果蝇的第二个基因。它编码的蛋白质产物与TGF-β相关的人类骨形态发生蛋白（BMP）5、6和7的相似性高于与果蝇dpp基因产物的相似性。由于其在多线染色体图谱上的定位，我们将该基因称为60A。利用果蝇S2细胞中60A cDNA的表达来确定60A编码一种前体蛋白原，该前体蛋白原经过加工后产生分泌型的氨基末端和羧基末端多肽。羧基末端肽以二硫键连接的同型二聚体形式回收。60A转录本和蛋白质首先在原肠胚形成开始时被检测到，主要存在于延伸的胚带的中胚层中。随着胚带收缩，以及在胚胎发育的后期阶段，60A转录本和蛋白质最容易在发育中的前肠和后肠细胞中被检测到。
