Wimer-Mackin S, Granger B L
Veterinary Molecular Biology Laboratory, Montana State University, Bozeman 59717-3610, USA.
Biochem Biophys Res Commun. 1996 Dec 13;229(2):472-8. doi: 10.1006/bbrc.1996.1828.
The Igp/LAMP family of mammalian and avian lysosomal type I membrane glycoproteins features short, conserved, cytosolic tails that possess lysosomal targeting information. The sequences of the adjacent transmembrane domains are also highly conserved, with six amino acids identical in all sixteen known Igp variants. These six residues are found along one side of a hypothetical alpha-helix that may comprise this domain. We substituted or deleted some of the conserved transmembrane residues in mouse Igp-A and stably expressed the proteins in Chinese hamster ovary cells. We examined various properties and transport characteristics of the normal and modified proteins and concluded that the transmembrane domain serves as more than just a membrane anchor, as it subtly influences the cellular distribution of the protein as well.
哺乳动物和鸟类溶酶体I型膜糖蛋白的Igp/LAMP家族具有短的、保守的胞质尾部，这些尾部具有溶酶体靶向信息。相邻跨膜结构域的序列也高度保守，在所有16种已知的Igp变体中，有6个氨基酸是相同的。这6个残基位于可能构成该结构域的假设α螺旋的一侧。我们在小鼠Igp-A中替换或删除了一些保守的跨膜残基，并在中国仓鼠卵巢细胞中稳定表达这些蛋白质。我们研究了正常和修饰蛋白质的各种特性和转运特征，得出结论：跨膜结构域不仅仅是一个膜锚定物，因为它也会微妙地影响蛋白质在细胞内的分布。
