Lyman S D, Stocking K, Davison B, Fletcher F, Johnson L, Escobar S
Immunex Research and Development Corporation, Seattle, Washington 98101, USA.
Oncogene. 1995 Sep 21;11(6):1165-72.
Both the murine and human genomic loci that encode flt3 ligand have been cloned. flt3 ligand is a hematopoietic growth factor that stimulates the proliferation of stem and progenitor cells. The portions of the murine and human flt3 ligand genomic loci encompassing the coding region of the protein are approximately 4.0 kb and 5.9 kb, respectively. The human genomic locus is larger as a result of the presence of repeated sequences within introns I, II, IV, V and VI. The transmembrane isoform of the murine and human flt3 ligand proteins are each encoded within seven exons (1-5 + 7 and 8). Analyses of flt3 ligand cDNA clones show that alternative splicing of a putative sixth exon results in the generation of a soluble form of the flt3 ligand protein. The sizes of each of the exons are well conserved between species. Murine and human flt3 genomic loci have a similar exon: intron structure compared to the genomic loci encoding Steel factor and colony stimulating factor 1. These proteins, which appear to be ancestrally related, are hematopoietic growth factors that stimulate cells via specific and structurally related tyrosine kinase receptors on the cell surface.
编码Flt3配体的小鼠和人类基因组位点均已被克隆。Flt3配体是一种造血生长因子，可刺激干细胞和祖细胞的增殖。小鼠和人类Flt3配体基因组位点中包含该蛋白质编码区的部分分别约为4.0 kb和5.9 kb。由于内含子I、II、IV、V和VI中存在重复序列，人类基因组位点更大。小鼠和人类Flt3配体蛋白的跨膜异构体均由七个外显子（1 - 5 + 7和8）编码。对Flt3配体cDNA克隆的分析表明，假定的第六外显子的可变剪接导致了Flt3配体蛋白可溶性形式的产生。各外显子的大小在物种间高度保守。与编码Steel因子和集落刺激因子1的基因组位点相比，小鼠和人类Flt3基因组位点具有相似的外显子：内含子结构。这些似乎具有祖先关系的蛋白质是造血生长因子，它们通过细胞表面特定的、结构相关的酪氨酸激酶受体刺激细胞。
