Yang F, Bergeron J M, Linehan L A, Lalley P A, Sakaguchi A Y, Bowman B H
Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio 78284.
Genomics. 1990 Aug;7(4):509-16. doi: 10.1016/0888-7543(90)90193-x.
The group-specific component (GC), also known as the vitamin D-binding protein, transports vitamin D and its metabolites in plasma to target tissues throughout the body. The GC gene shares an evolutionary origin with genes encoding albumin (ALB) and alpha-fetoprotein (AFP). All three genes are descendants of an evolutionary ancestor that arose from an intragenic triplication. As a result, each gene is composed of three homologous domains. The study described here characterizes and compares mouse GC to the corresponding nucleotide and amino acid sequences of GC from human and rat. The deduced amino acid sequence of mouse GC was 78% identical to human and 91% identical to rat GC. The results suggest that, unlike the corresponding sequences in the ALB and AFP genes, chromosomal sequences encoding the first domain and the leader sequence of the GC gene have specifically been conserved throughout vertebrate evolution. Protection of domain I during evolution may correlate with an important functional aspect of its sequence. The mouse GC gene was mapped to chromosome 5, where the ALB and AFP genes are also located, demonstrating conservation of the three genes in vertebrate species.
群体特异性成分（GC），也称为维生素D结合蛋白，可将血浆中的维生素D及其代谢产物转运至全身的靶组织。GC基因与编码白蛋白（ALB）和甲胎蛋白（AFP）的基因有着共同的进化起源。这三个基因均源自一个通过基因内重复产生的进化祖先。因此，每个基因都由三个同源结构域组成。本文所述的研究对小鼠GC与人类和大鼠GC的相应核苷酸及氨基酸序列进行了表征和比较。小鼠GC推导的氨基酸序列与人类的一致性为78%，与大鼠GC的一致性为91%。结果表明，与ALB和AFP基因的相应序列不同，编码GC基因第一个结构域和前导序列的染色体序列在整个脊椎动物进化过程中得到了特异性保留。进化过程中结构域I的保留可能与其序列的重要功能方面相关。小鼠GC基因被定位到5号染色体，ALB和AFP基因也位于该染色体上，这表明这三个基因在脊椎动物物种中具有保守性。
