对血小板胞质钙离子浓度升高的响应
中文名称
通路描述
磷脂酶 C 酶活性的激活导致磷脂酰肌醇途径的第二信使产生。该途径的结果是细胞内钙离子浓度升高和蛋白激酶 C（PKC）的激活。磷脂酶 C 将 PIP2 中的磷脂酰酯键水解，生成 1,2-二酰甘油（DAG）和 1,4,5-肌醇三磷酸（IP3）。IP3 打开血小板密集管系统中的钙离子通道，升高细胞内钙离子浓度。DAG 是一种第二信使，调节一种由 PKC 同工酶组成的 Ser/Thr 激酶家族（Nishizuka 1995）。DAG 通过增加其亲和力与磷脂结合来激活 PKC 同工酶。大多数 PKC 酶也依赖于钙离子，因此它们的激活与细胞内钙离子浓度的升高协同作用。血小板含有几种可由 DAG 和/或钙离子激活的 PKC 同工酶（Chang 1997）。
英文描述
Keratan sulfate biosynthesis Three keratan sulfate polymers have been found (KS-I, KS-II, KS-III) bound to core proteins. KS-I is the best characterised keratan sulfate. It is 10 times more abundant in cornea than cartilage. KS-I is elongated by the alternate additions of galactose (Gal) and N-acetylglucosamine (GlcNAc), mediated by glycosyltransferases. Elongation is often terminated by the addition of a single N-acetylneuraminic acid (sialyl) or a fucose residue. KS-I is also sulfated on many Gal and GlcNAc residues by at least two sulfotransferases (reviewed in Caterson & Melrose, 2018; Funderburgh 2000, Funderburgh 2002, Quantock et al. 2010). These reactions are running in parallel which we cannot represent in the diagram. The intermediate reaction products shown are therefore only for demonstration purposes.
所含基因
29 个基因