Clark C C, Cohen I, Eichstetter I, Cannizzaro L A, McPherson J D, Wasmuth J J, Iozzo R V
Department of Pathology and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
Genomics. 1993 Nov;18(2):249-60. doi: 10.1006/geno.1993.1463.
The highly conserved Wnt genes belong to a widely distributed family of presumptive signaling molecules that have been implicated not only in the regulation of normal pattern formation during embryogenesis and differentiation of cell lineages, but also in oncogenic events. All of the known vertebrate Wnt genes encode for 38- to 43-kDa cysteine-rich putative glycoproteins, which have features typical of secreted growth factors: a hydrophobic signal sequence, a conserved asparagine-linked oligosaccharide consensus sequence, and 22 conserved cysteine residues whose relative spacing is maintained. In this study, we report the cloning and sequencing of several overlapping cDNAs encoding approximately 4.1 kb of the human homologue of Wnt-5A. The mature protein contained 343 residues (M(r) approximately 38,000 excluding any post-translational modifications) with a > 93% homology to the reported sequences of other Wnt-5A proteins (> 99% homologous to mouse Wnt-5A). This protein maintained certain features--a hydrophobic signal sequence, the Wnt-1 family "signature sequence" (CKCHGvSGSC), and a number of other conserved amino acid residues: 24 cysteine residues, 4 asparagine-linked oligosaccharide consensus sequences, and a tyrosine sulfation site--that have been found in all other Wnt-5A proteins. Reverse transcriptase PCR analysis of RNA from a variety of human embryonic, neonatal, and adult cells and/or tissues showed that human Wnt-5A expression was detected only in neonatal heart and lung. It may be relevant, however, that the 3'-untranslated region contained numerous AT-rich motifs that could be involved in the rapid degradation of mRNA. Finally, using a combination of Southern blotting, PCR amplification, and in situ hybridization, the human Wnt-5A (WNT5A) gene was mapped to chromosome 3p14-p21.
高度保守的Wnt基因属于一个广泛分布的假定信号分子家族，它们不仅与胚胎发育过程中正常模式形成的调控以及细胞谱系的分化有关，还与致癌事件有关。所有已知的脊椎动物Wnt基因编码38至43 kDa富含半胱氨酸的假定糖蛋白，这些蛋白具有分泌型生长因子的典型特征：一个疏水信号序列、一个保守的天冬酰胺连接寡糖共有序列以及22个保守的半胱氨酸残基，其相对间距得以保持。在本研究中，我们报告了几个重叠cDNA的克隆和测序，这些cDNA编码约4.1 kb的人类Wnt-5A同源物。成熟蛋白包含343个氨基酸残基（不包括任何翻译后修饰，Mr约为38,000），与其他Wnt-5A蛋白的报道序列具有> 93%的同源性（与小鼠Wnt-5A的同源性> 99%）。该蛋白保留了某些特征——一个疏水信号序列、Wnt-1家族“特征序列”（CKCHGvSGSC）以及许多其他保守氨基酸残基：24个半胱氨酸残基、4个天冬酰胺连接寡糖共有序列以及一个酪氨酸硫酸化位点——这些特征在所有其他Wnt-5A蛋白中都已发现。对来自多种人类胚胎、新生儿和成人细胞及/或组织的RNA进行逆转录酶PCR分析表明，仅在新生儿心脏和肺中检测到人类Wnt-5A表达。然而，3'-非翻译区包含许多富含AT的基序，这些基序可能参与mRNA的快速降解，这一点可能具有相关性。最后，通过Southern印迹、PCR扩增和原位杂交相结合的方法，将人类Wnt-5A（WNT5A）基因定位到染色体3p14 - p21。
