Owen M J, Kissonerghis A M, Lodish H F
J Biol Chem. 1980 Oct 25;255(20):9678-84.
The biosynthesis of the HLA-A and -B antigens was studied in the B lymphoblastoid cell line BRI 8 and the Burkitt lymphoma line DAudi. The heavy chains of the HLA-A and -B antigens were inserted asymmetrically into the rough endoplasmic reticulum of BRI 8 cells as transmembrane polypeptides. During the first 5 min after synthesis, the majority of the heavy chains became associated with beta 2-microglobulin. At this stage, the heavy chains carried a high mannose (core) oligosaccharide. Subsequent processing of the oligosaccharide unit occurred during the next 20 to 25 min, resulting in the conversion of the oligosaccharide from the high mannose to the complex form. About 30 to 40 min after synthesis, the mature antigens were expressed at the cell surface. Glycosylation was not required for asymmetric insertion, intracellular transport, or surface expression of the HLA-A and -B antigens. However, studies with Daudi cells indicated that combination with beta 2-microglobulin was necessary for subsequent processing and intracellular transport of the heavy chains after their synthesis in the rough endoplasmic reticulum.
在B淋巴母细胞系BRI 8和伯基特淋巴瘤系DAudi中研究了HLA - A和 - B抗原的生物合成。HLA - A和 - B抗原的重链作为跨膜多肽不对称地插入到BRI 8细胞的粗面内质网中。在合成后的最初5分钟内，大多数重链与β2 -微球蛋白结合。在此阶段，重链携带高甘露糖（核心）寡糖。寡糖单元的后续加工在接下来的20至25分钟内发生，导致寡糖从高甘露糖形式转变为复杂形式。合成后约30至40分钟，成熟抗原在细胞表面表达。HLA - A和 - B抗原的不对称插入、细胞内运输或表面表达不需要糖基化。然而，对Daudi细胞的研究表明，重链在粗面内质网中合成后，与β2 -微球蛋白结合对于其后续加工和细胞内运输是必要的。
