Identification of a partial cDNA clone for the C3d/Epstein-Barr virus receptor of human B lymphocytes: homology with the receptor for fragments C3b and C4b of the third and fourth components of complement.
Identification of a partial cDNA clone for the C3d/Epstein-Barr virus receptor of human B lymphocytes: homology with the receptor for fragments C3b and C4b of the third and fourth components of complement.
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人 B 淋巴细胞 C3d/Epstein-Barr 病毒受体的部分 cDNA 克隆的鉴定：与补体第三和第四成分的片段 C3b 和 C4b 的受体同源性。
DOI：
10.1073/pnas.83.15.5639
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发表时间：
1986
影响因子：
11.1
通讯作者：
Weis,JH
中科院分区：
文献类型：
--
作者：
Weis,JJ;Fearon,DT;Klickstein,LB;Wong,WW;Richards,SA;deBruynKops,A;Smith,JA;Weis,JH
人补体受体2型（CR2）是补体第三组分C3 d片段和EB病毒的B淋巴细胞受体。CR2的胰蛋白酶肽的氨基酸序列分析揭示了与人C3 b/C4 b受体CR 1的高度同源性。这种同源性表明，CR 1基因序列可用于在低严格杂交条件下检测CR2序列。在用CR 1 cDNA序列筛选人扁桃体cDNA文库时，鉴定出两个在低严格性下杂交而不是在高严格性下杂交的克隆。合成对CR2序列特异的冗余寡核苷酸，并用于确定与CR 1 cDNA弱杂交的两个cDNA克隆含有CR2序列。这些CR2 cDNA克隆之一与来自两种不同的CR2胰蛋白酶肽的寡核苷酸杂交，而另一个较小的cDNA克隆与仅来自一种CR2肽的寡核苷酸杂交。CR2 cDNA的核苷酸序列分析证实，寡核苷酸杂交的位点与从肽序列预测的相同，包括不包括在寡核苷酸探针内的侧翼序列。CR 2特异性cDNA序列鉴定了从人B细胞提取的RNA中5种腺苷酸酶的聚（A）+ RNA种类，但不与从CR 2阴性T细胞系HSB-2获得的任何RNA杂交，从而证实了CR 2 mRNA的适当大小和组织特异性分布。CR2和CR 1之间惊人的肽序列同源性以及CR2 cDNA与CR 1特异性序列的交叉杂交允许将CR2置于最近定义的C3和C4结合蛋白的基因家族中，该基因家族由CR 1、C4结合蛋白、因子H和现在的CR2组成。
Human complement receptor type 2 (CR2) is the B-lymphocyte receptor both for the C3d fragment of the third component of complement and for the Epstein-Barr virus. Amino acid sequence analysis of tryptic peptides of CR2 revealed a strong degree of homology with the human C3b/C4b receptor, CR1. This homology suggested that CR1 gene sequences could be used to detect the CR2 sequences at conditions of low-stringency hybridization. Upon screening a human tonsillar cDNA library with CR1 cDNA sequences, two clones were identified that hybridized at low, but not at high, stringency. Redundant oligonucleotides specific for CR2 sequences were synthesized and used to establish that the two cDNA clones weakly hybridizing with the CR1 cDNA contained CR2 sequences. One of these CR2 cDNA clones hybridized to oligonucleotides derived from two distinct CR2 tryptic peptides, whereas the other, smaller cDNA clone hybridized to oligonucleotides derived from only one of the CR2 peptides. Nucleotide sequence analysis of the CR2 cDNA confirmed that the site of oligonucleotide hybridization was identical to that predicted from the peptide sequence, including flanking sequences not included within the oligonucleotide probes. The CR2-specific cDNA sequences identified a poly(A)+ RNA species of 5 kilobases in RNA extracted from human B cells but did not hybridize to any RNA obtained from the CR2-negative T-cell line HSB-2, thus confirming the appropriate size and tissue-specific distribution for the CR2 mRNA. The striking peptide sequence homology between CR2 and CR1 and the cross-hybridization of the CR2 cDNA with the CR1-specific sequences allow the placement of CR2 in a recently defined gene family of C3- and C4-binding proteins consisting of CR1, C4-binding protein, factor H, and now, CR2.