黏液素
黏液素是一类高分子量蛋白家族,且高度糖基化(属于),在大部分后生动物的上皮组织中都有表达 Mucins' key characteristic is their ability to form gels; therefore they are a key component in most gel-like secretions, serving functions from lubrication to cell signalling to forming chemical barriers. calcification in echinoderms and bone formation in vertebrates. They bind to pathogens as part of the immune system. Overexpression of the mucin proteins, especially MUC1, is associated with many types of cancer.
Although some mucins are membrane-bound due to the presence of a hydrophobic membrane-spanning domain that favors retention in the plasma membrane, most mucins are secreted onto mucosal surfaces or secreted to become a component of saliva.
基因
通过cDNA克隆发现了至少19个人类黏素基因——MUC1、MUC2、MUC3A、MUC3B、MUC4、MUC5AC、MUC5B、MUC6、MUC7、MUC8、MUC12、MUC13、MUC15、MUC16、MUC17、MUC19和MUC20。
主要分泌于呼吸道的黏素是MUC5AC和MUC5B,而MUC2主要分泌于小肠,在呼吸道中也有出现。