Li Y, Wong A, Szabo P, Posnett D N
Department of Medicine, Cornell University Medical College, New York, NY 10021.
Immunogenetics. 1993;37(5):347-55. doi: 10.1007/BF00216799.
Tcrb-V6.10 represents an abnormal human V gene with an Alu insertion in the promoter, a point mutation of a conserved Cys at position 23, and a missing nonamer within the usually conserved recombinase signal sequence. Here it is shown that b-V6.10 is found in the genome of most individuals, is normally located in the Tcrb-V locus on chromosome 7, but is not rearranged or transcribed. Thus, it is likely that the abnormal signal sequence precludes recombination and that the Alu insertion results in a disabled promoter, indicating the functional importance of the affected regions. Tcrb-V6.10 probably evolved by duplication of an ancestral Tcrb V13-V6-V5 cassette, like other members of the large b-V6 subfamily, and more recently became inactivated into a pseudogene.
Tcrb-V6.10代表一种异常的人类V基因,其启动子中有一个Alu插入序列,第23位保守半胱氨酸发生点突变,并且在通常保守的重组信号序列内缺少一个九聚体。本文表明,b-V6.10存在于大多数个体的基因组中,正常定位于7号染色体上的Tcrb-V基因座,但不发生重排或转录。因此,异常的信号序列可能会阻止重组,而Alu插入会导致启动子失活,这表明受影响区域具有功能重要性。Tcrb-V6.10可能是通过祖先的Tcrb V13-V6-V5基因盒的复制而进化而来,就像大的b-V6亚家族的其他成员一样,并且最近失活成为一个假基因。