F8

This gene encodes coagulation factor VIII, which participates in the intrinsic pathway of blood coagulation; factor VIII is a cofactor for factor IXa which, in the presence of Ca+2 and phospholipids, converts factor X to the activated form Xa. This gene produces two alternatively spliced transcripts. Transcript variant 1 encodes a large glycoprotein, isoform a, which circulates in plasma and associates with von Willebrand factor in a noncovalent complex. This protein undergoes multiple cleavage events. Transcript variant 2 encodes a putative small protein, isoform b, which consists primarily of the phospholipid binding domain of factor VIIIc. This binding domain is essential for coagulant activity. Defects in this gene results in hemophilia A, a common recessive X-linked coagulation disorder. [provided by RefSeq, Jul 2008]

本基因编码凝血因子VIII，该因子参与血液凝固的内源性途径；因子VIII作为因子IXa的辅因子，在钙离子和磷脂的存在下，将因子X转化为活化形式Xa。此基因产生两种选择性剪接的转录本。转录本变异1编码一种大型糖蛋白，即同型a，该蛋白在血浆中循环，并与冯·威勒布兰德因子形成一个非共价复合物。该蛋白经历多次切割事件。转录本变异2编码一种假定的小型蛋白，即同型b，主要由凝血因子VIIIc的磷脂结合域组成。此结合域对于凝血活性至关重要。该基因的缺陷导致血友病A，一种常见的隐性X连锁凝血疾病。（由RefSeq提供，2008年7月）