Wiskott-Aldrich syndrome/X-linked thrombocytopenia: WASP gene mutations, protein expression, and phenotype
Wiskott-Aldrich syndrome/X-linked thrombocytopenia: WASP gene mutations, protein expression, and phenotype
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DOI：
10.1182/blood.v90.7.2680.2680_2680_2689
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发表时间：
1997-10-01
期刊：
影响因子：
20.3
通讯作者：
Ochs, HD
中科院分区：
文献类型：
--
作者：
Zhu, QL;Watanabe, C;Ochs, HD
Wiskott-Aldrich综合征(Was)和X-连锁血小板减少症(XLT)是由Wiskott-Aldrich综合征蛋白(WASP)基因突变引起的，代表同一疾病的不同表型。为了证明表型/基因型的相关性，我们在48个无关的IS家系中检测了WASP基因突变。突变包括错义突变(20个家系)和无义突变(8个)，主要位于外显子1到4，剪接点突变(7个)和缺失和插入(13个)优先位于外显子7到11。对基因组DNA和cDNA进行测序，并用兔抗WASP多肽抗体检测细胞裂解物中WASP的表达。WASP在包括骨髓源性CD34(+)细胞在内的造血细胞系中表达。位于外显子1至3的错义突变导致除一个家系外的所有家系都患有轻度疾病，并允许WASP表达，尽管通常浓度较低。影响外显子4的错义突变与经典的AS有关，除了一个例外，几乎检测不到WASP。无义突变导致典型的AS和蛋白质缺乏。插入、缺失和剪接位点突变导致经典的和缺失的、不稳定的、截断的或倍增的剪接蛋白。通过亲和沉淀，发现Wasp能与含有Src SH3的蛋白Fyn、Lck、PLC-Gamma和Grb2结合，突变的Wasp如果表达，能够与Fyn-Glutathione S转移酶(GST)融合蛋白结合。我们的结论是，影响WASP的PH结构域(外显子1至3)的错义突变抑制了蛋白质的次要功能，导致了轻微的表型，而影响外显子4的错义突变和影响WASP 3‘部分的复杂突变干扰了蛋白质的关键功能，并导致了经典的AS。(C)1997年由美国血液病学会主办。
Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT), caused by mutations of the WAS protein (WASP) gene, represent different phenotypes of the same disease. To demonstrate a phenotype/genotype correlation, we determined WASP gene mutations in 48 unrelated WAS families. Mutations included missense (20 families) and nonsense (eight) mutations located mostly in exons 1 to 4, and splice-site mutations (seven) and deletions and insertions (13) located preferentially in exons 7 to 11. Both genomic DNA and cDNA were sequenced and WASP expression was measured in cell lysates using peptide-specific rabbit anti-WASP antibodies. WASP was expressed in hematopoietic cell lines including bone marrow-derived CD34(+) cells. Missense mutations located in exons 1 to 3 caused mild disease in all but one family and permitted WASP expression, although frequently at decreased concentration. Missense mutations affecting exon 4 were associated with classic WAS and, with one exception, barely detectable WASP. Nonsense mutations caused classic WAS and lack of protein. Insertions, deletions, and splice-site mutations resulted in classic WAS and absent, unstable, truncated, or multiply spliced protein. Using affinity precipitation, WASP was found to bind to Src SH3-containing proteins Fyn, Lck, PLC-gamma,and Grb2, and mutated WASP, if expressed, was able to bind to Fyn-glutathione S-transferase (GST) fusion protein. We conclude that missense mutations affecting the PH domain (exons 1 to 3) of WASP inhibit less important functions of the protein and result in a mild phenotype, and that missense mutations affecting exon 4 and complex mutations affecting the 3' portion of WASP interfere with crucial functions of the protein and cause classic WAS. (C) 1997 by The American Society of Hematology.