Crabtree G R, Kant J A
Cell. 1982 Nov;31(1):159-66. doi: 10.1016/0092-8674(82)90415-9.
In a variety of species, including rodents and man, the gamma chain of fibrinogen consists of two nonallelic forms, called gamma A and gamma B, or gamma and gamma '. We have found that these two fibrinogen gamma chains in the rat arise by translation of two mRNAs of 1700 and 2200 nucleotides, which are produced from a single gene by alternative splice patterns. The more abundant, gamma A chain mRNA is 1561 nucleotides long, excluding the polyadenylated region, and encodes a protein 83% homologous with the human gamma A chain. A hydrophobic "signal" polypeptide of 25 amino acids is present at the amino terminus. The gamma B (gamma ') mRNA is identical with the gamma A sequence with the exception of a 513 bp insert located 202 bp from the poly(A) extension. This 513 bp insert is identical to the seventh and final intron of the gamma-fibrinogen gene, and is located four codons prior to the termination codon for the gamma A chain. Translation into this sequence produces a unique 12 amino acid carboxylterminus in the rat gamma B (gamma ') polypeptide that is homologous with the known carboxylterminus of the human gamma B (gamma ') chain.
在包括啮齿动物和人类在内的多种物种中，纤维蛋白原的γ链由两种非等位形式组成，称为γA和γB，或γ和γ'。我们发现，大鼠中的这两种纤维蛋白原γ链是由1700和2200个核苷酸的两种mRNA翻译产生的，它们通过可变剪接模式由单个基因产生。含量更丰富的γA链mRNA长度为1561个核苷酸，不包括聚腺苷酸化区域，编码一种与人类γA链有83%同源性的蛋白质。在氨基末端存在一个由25个氨基酸组成的疏水“信号”多肽。γB（γ'）mRNA与γA序列相同，只是在距离聚（A）延伸202 bp处有一个513 bp的插入片段。这个513 bp的插入片段与γ-纤维蛋白原基因的第七个也是最后一个内含子相同，位于γA链终止密码子之前的四个密码子处。翻译成这个序列会在大鼠γB（γ'）多肽中产生一个独特的12个氨基酸的羧基末端，它与人类γB（γ'）链的已知羧基末端同源。
