Masiakowski P, Carroll R D
Regeneron Pharmaceuticals, Tarrytown, New York 10591-6707.
J Biol Chem. 1992 Dec 25;267(36):26181-90.
Human cDNA clones encoding two novel proteins with a region strongly homologous to the tyrosine kinase domain of growth factor receptors, in particular of the Trk family, were obtained by a polymerase chain reaction-based approach. These proteins, Ror1 and Ror2, share 58% overall amino acid identity and a structure indicative of cell surface molecules. A secretion signal sequence and a transmembrane domain delimit the extracellular portion, which contains immunoglobulin-like, cysteine-rich, and kringle domains. The cytoplasmic portion contains the tyrosine kinase-like domain which (in Ror2) appears to be associated with protein kinase activity in vitro, followed by serine/threonine- and proline-rich motifs. Partial nucleotide sequences of the rat genes reveal striking evolutionary conservation of the proteins between human and rat. The level of expression of the rat genes is high in the head and body of early embryo and decreases dramatically after embryonic day 16. Based on these data, Ror1 and Ror2 appear to define a new developmentally regulated family of cell surface receptors for unidentified ligands.
通过基于聚合酶链反应的方法，获得了编码两种新型蛋白质的人cDNA克隆，这些蛋白质具有与生长因子受体（特别是Trk家族）的酪氨酸激酶结构域高度同源的区域。这些蛋白质Ror1和Ror2的氨基酸序列总体一致性为58%，具有细胞表面分子的结构特征。分泌信号序列和跨膜结构域界定了细胞外部分，该部分包含免疫球蛋白样、富含半胱氨酸和kringle结构域。细胞质部分包含酪氨酸激酶样结构域（在Ror2中），体外实验表明其似乎与蛋白激酶活性相关，随后是富含丝氨酸/苏氨酸和脯氨酸的基序。大鼠基因的部分核苷酸序列显示，人与大鼠之间的蛋白质具有显著的进化保守性。大鼠基因在早期胚胎的头部和身体中表达水平较高，在胚胎第16天后急剧下降。基于这些数据，Ror1和Ror2似乎定义了一个新的受发育调控的细胞表面受体家族，其配体尚未明确。
