Grandea A G, Comber P G, Wenderfer S E, Schoenhals G, Früh K, Monaco J J, Spies T
Fred Hutchinson Cancer Research Center, Clinical Research Division, 1100 Fairview Ave. N., Seattle, WA 98109, USA.
Immunogenetics. 1998 Sep;48(4):260-5. doi: 10.1007/s002510050430.
Assembly of major histocompatibility complex (MHC) class I molecules in human cells is dependent on the accessory protein tapasin, which mediates their interaction with the transporters associated with antigen processing (TAP) and thereby ensures efficient peptide binding. Analysis of a mouse tapasin complementary DNA defined a conserved polypeptide sharing sequences diagnostic of a transmembrane protein related to the immunoglobulin superfamily, and an endoplasmic reticulum retention motif. The mouse tapasin gene was mapped about 70 kilobases from H2-K at the centromeric end of the mouse MHC. Expression of mouse tapasin in a tapasin-deficient human mutant cell line restored the normal assembly and expression of class I alleles. Thus, tapasin is a structurally and functionally conserved component of the MHC class I antigen processing pathway. Its genetic linkage to the class I and TAP subunit genes in the MHC may be of significance in the coordinate expression and functional coadaptation of the diverse gene products.
人类细胞中主要组织相容性复合体（MHC）I类分子的组装依赖于辅助蛋白塔帕辛，它介导MHC I类分子与抗原加工相关转运体（TAP）的相互作用，从而确保有效的肽结合。对小鼠塔帕辛互补DNA的分析确定了一种保守的多肽，该多肽具有与免疫球蛋白超家族相关的跨膜蛋白的诊断序列，以及一个内质网滞留基序。小鼠塔帕辛基因被定位在小鼠MHC着丝粒端距H2-K约70千碱基处。在缺乏塔帕辛的人类突变细胞系中表达小鼠塔帕辛可恢复I类等位基因的正常组装和表达。因此，塔帕辛是MHC I类抗原加工途径中结构和功能保守的成分。它与MHC中的I类和TAP亚基基因的遗传连锁可能对多种基因产物的协调表达和功能协同适应具有重要意义。
