Antisense transcripts of V(D)J rearrangements; artifacts caused by false priming?
Antisense transcripts of V(D)J rearrangements; artifacts caused by false priming?
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V(D)J 重排的反义转录本；
DOI：
10.1016/j.molimm.2009.03.020
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发表时间：
2009
影响因子：
3.6
通讯作者：
Zhao Y
中科院分区：
文献类型：
--
作者：
Zhao Y
IGH和IGL基因座上V（D）J重排的体细胞超突变（SH）在生发中心反应期间使IG库多样化。SH完全依赖于酶激活诱导的胞苷脱氨酶（AID），其通过使ssDNA中的C核苷酸脱氨基来启动SH过程。G和C的突变被认为是由于编码链和非编码链上的AID分别对C进行链对称脱氨基而发生的。在AID诱导的损伤的易错修复期间，以链偏向的方式引入来自A和T的突变。SH与转录相关，并且已经提出在活化和静止B细胞中发生跨越V（D）J重排的双向转录，并且其被增选以通过调节单链DNA对AID的可接近性来促进两条DNA链的可接近性。我们发展了一种定量研究定向转录的方法。我们的方法控制逆转录的效率和特异性差异，已知这些差异能够产生假阳性数据。该方法在自发超突变细胞系拉莫斯或人血B细胞或扁桃体细胞的超突变结构域内的外显子或内含子区域中未检测到反义转录物，这提供了令人信服的证据，证明反义转录物在人B细胞中是罕见的或不存在的。
Somatic hypermutation (SH) of V(D)J rearrangements at the IGH and IGL loci diversifies the IG repertoire during the germinal center response. SH is absolutely dependent on the enzyme activation induced cytidine deaminase (AID) that initiates the SH process by deaminating C nucleotides in ssDNA. Mutations from G and C are thought to occur as a result of strand symmetrical deamination of C by AID on the coding and non-coding strands respectively. Mutations from A and T are introduced in a strand biased way during error prone repair of the AID induced lesion. SH is linked to transcription and it has been proposed that bidirectional transcription across V(D)J rearrangements occurs in activated and quiescent B cells and that it is co-opted to facilitate the accessibility of the two DNA strands by regulating accessibility of single stranded DNA to AID. We have developed a quantitative method to study directional transcription. Our method controls for differences in efficiency and specificity of reverse transcription that are known to be able to generate false positive data. This method does not detect antisense transcripts in exonic or intronic regions within the hypermutation domain of the spontaneously hypermutating cell line Ramos, or in human blood B cells or tonsil cells, providing convincing evidence that antisense transcripts are rare or absent in human B cells.
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通过体细胞超突变靶向非 Ig 序列代替 V 片段
影响因子：
64.8
作者：
J. Yélamos;N. Klix;B. Goyenechea;F. Lozano;Y. Chui;A. G. FernÃndez;R. Pannell;M. Neuberger;C. Milstein
通讯作者：
C. Milstein
DOI：
10.1073/pnas.95.15.8791
发表时间：
1998-07-21
影响因子：
11.1
作者：
Milstein, C;Neuberger, MS;Staden, R
通讯作者：
Staden, R
影响因子：
32.4
作者：
Sale, JE;Neuberger, MS
通讯作者：
Neuberger, MS
IgVH 基因中各个核苷酸取代周围的序列特征表明存在不同的 GC 和 AT 突变子。
影响因子：
4.4
作者：
J. Spencer;M. Dunn;D. Dunn
通讯作者：
D. Dunn