Shirozu M, Nakano T, Inazawa J, Tashiro K, Tada H, Shinohara T, Honjo T
Department of Medical Chemistry, Kyoto University Faculty of Medicine, Japan.
Genomics. 1995 Aug 10;28(3):495-500. doi: 10.1006/geno.1995.1180.
Stromal cell-derived factors 1 alpha and 1 beta are small cytokines belonging to the intercrine CXC subfamily and originally isolated from a murine bone-marrow stroma cell line by the signal sequence trap method. cDNA and genomic clones of human SDF1 alpha and SDF1 beta (SDF1A and SDF1B) were isolated and characterized. cDNAs of SDF1 alpha and SDF1 beta encode proteins of 89 and 93 amino acids, respectively. SDF1 alpha and SDF1 beta sequences are more than 92% identical to those of the human counterparts. The genomic structure of the SDF1 gene revealed that human SDF1 alpha and SDF1 beta are encoded by a single gene and arise by alternative splicing. SDF1 alpha and SDF1 beta are encoded by 3 and 4 exons, respectively. Ubiquitous expression of the SDF1 gene, except in blood cells, was consistent with the presence of the GC-rich sequence in the 5'-flanking region of the SDF1 gene, as is often the case in the "housekeeping" genes. Although genes encoding other members of the intercrine family are localized on chromosome 4q or 17q, the human SDF1 gene was mapped to chromosome 10q by fluorescence in situ hybridization. Strong evolutionary conservation and unique chromosomal localization of the SDF1 gene suggest that SDF1 alpha and SDF1 beta may have important functions distinct from those of other members of the intercrine family.
基质细胞衍生因子1α和1β是属于细胞间CXC亚家族的小细胞因子，最初通过信号序列捕获法从小鼠骨髓基质细胞系中分离得到。人SDF1α和SDF1β（SDF1A和SDF1B）的cDNA和基因组克隆已被分离并鉴定。SDF1α和SDF1β的cDNA分别编码89个和93个氨基酸的蛋白质。SDF1α和SDF1β的序列与人类对应序列的同一性超过92%。SDF1基因的基因组结构显示，人SDF1α和SDF1β由单个基因编码，并通过可变剪接产生。SDF1α和SDF1β分别由3个和4个外显子编码。SDF1基因在除血细胞外的组织中广泛表达，这与SDF1基因5'侧翼区域存在富含GC的序列一致，这在“管家”基因中很常见。尽管编码细胞间家族其他成员的基因定位于4号染色体q区或17号染色体q区，但通过荧光原位杂交将人SDF1基因定位于10号染色体q区。SDF1基因强大的进化保守性和独特的染色体定位表明，SDF1α和SDF1β可能具有与细胞间家族其他成员不同的重要功能。
