Sittisombut N, Mordacq J, Knight K L
Department of Microbiology and Immunology, University of Illinois, College of Medicine, Chicago 60612.
J Immunol. 1988 May 1;140(9):3237-43.
Molecular genetics studies have recently revealed complexity in the MHC class II region that has not been detected by previous serologic and genetic studies. In humans, three subregions, DP, DQ, and DR, of the class II genes as well as the DZ alpha and DO beta genes, have been extensively characterized. Although homologs of these human genes were identified in many species, their expressibility has not been well defined in species other than the mouse. We have previously cloned the rabbit homologs of the HLA-DP alpha and beta genes whose protein products had never been detected. The sequences of rabbit DP alpha 1 and DP beta genes are reported herein and they indicate that the rabbit DP genes encode functional alpha- and beta-chains. Unfavorable nucleotides surrounding the first AUG codon may, however, reduce the translational efficiency of the R-DP beta mRNA and explain the difficulty in generating serologic reagents specific for rabbit DP molecules. A complex mutation in the beta 1 domain of the R-DP beta gene was similar to the one found in the H-2A beta 1 gene of five strains of mice. The origin of this mutation is discussed.
分子遗传学研究最近揭示了MHC II类区域的复杂性，这是以前的血清学和遗传学研究未曾发现的。在人类中，II类基因的三个亚区域，即DP、DQ和DR，以及DZα和DOβ基因，已得到广泛的表征。尽管在许多物种中都鉴定出了这些人类基因的同源物，但除小鼠外，它们在其他物种中的表达情况尚未得到很好的界定。我们之前克隆了HLA-DPα和β基因的兔同源物，其蛋白质产物从未被检测到。本文报道了兔DPα1和DPβ基因的序列，这些序列表明兔DP基因编码功能性的α链和β链。然而，第一个AUG密码子周围不利的核苷酸可能会降低R-DPβ mRNA的翻译效率，并解释了难以产生针对兔DP分子的血清学试剂的原因。R-DPβ基因β1结构域中的一个复杂突变与在五个小鼠品系的H-2Aβ1基因中发现的突变相似。本文讨论了这种突变的起源。
