Mast cell number in the skin of heterozygotes reflects the molecular nature of c-kit mutation.
Mast cell number in the skin of heterozygotes reflects the molecular nature of c-kit mutation.
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DOI：
10.1182/blood.v81.10.2530.bloodjournal81102530
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发表时间：
1993-05
期刊：
影响因子：
20.3
通讯作者：
T. Tsujimura;H. Katoh;K. Isozaki;Y. Kanakura;T. Tono;S. Adachi;T. Kasugai;Hideki Tei;Y. Nishimune;S. Nomura;Yukihiko Kitamura
中科院分区：
文献类型：
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作者：
T. Tsujimura;H. Katoh;K. Isozaki;Y. Kanakura;T. Tono;S. Adachi;T. Kasugai;Hideki Tei;Y. Nishimune;S. Nomura;Yukihiko Kitamura
小鼠的W基因座编码c-kit受体酪氨酸激酶。杂合子WJic/+和Wn/+小鼠和纯合子Wf/Wf小鼠在外观上相似;它们都有大的脱色区域，缺乏任何明确的模式。WJic，Wn和Wf突变等位基因的特点，其分子性质与肥大细胞在皮肤中的分化和培养的肥大细胞（CMC）的生物学特性。所有WJic、Wn和Wf都是酪氨酸激酶结构域的点突变，并且c-kit mRNA从所有这些都正常转录。成熟的145-Kd形式的c-kit蛋白产生的WJic和Wf等位基因，但不是从Wn等位基因。WJic和Wf等位基因产生的c-kit蛋白在CMCs表面表达，而Wn等位基因不表达。当W和WJic之间以及W和Wn之间产生双杂合子小鼠时，W/WJic和W/Wn小鼠都缺乏皮肤肥大细胞。W/WJic CMCs和W/Wn CMCs在与成纤维细胞的共培养中不能存活。W/WJic CMCs正常粘附于成纤维细胞，而W/Wn CMCs不粘附于成纤维细胞。W/Wn型CMC在贴壁中的缺陷归因于c-kit蛋白的细胞外表达缺陷。比较了WJic/+、Wn/+、Wf/+和Wf/Wf小鼠皮肤肥大细胞的数量。肥大细胞在WJic/+和Wf/Wf小鼠中减少，但在Wn/+和Wf/+小鼠中不减少。虽然Wn是激酶结构域的点突变，但Wn的生物学效应与W突变等位基因的生物学效应相当，W突变等位基因产生截短的c-kit蛋白而没有跨膜结构域。Wn/+小鼠的弱表型可以通过Wn等位基因产生的c-kit蛋白的细胞外表达缺陷来解释。当重组c-kit配体刺激WJic/WJic、Wn/Wn和Wf/Wf CMC时，仅在Wf/Wf CMC中观察到自磷酸化活性。这一结果与Wf突变等位基因的弱生物学效应一致。
The W locus of mice encodes the c-kit receptor tyrosine kinase. Heterozygous WJic/+ and Wn/+ mice and homozygous Wf/Wf mice were similar in appearance; all of them have large depigmented areas lacking any well-defined pattern. The WJic, Wn, and Wf mutant alleles were characterized and their molecular nature was correlated with the mast cell differentiation in the skin and the biologic features of cultured mast cell (CMC). All WJic, Wn, and Wf were point mutations at the tyrosine kinase domain, and c-kit mRNA was normally transcribed from all of them. The mature 145-Kd form of the c-kit protein was produced from the WJic and Wf alleles, but not from the Wn allele. c-kit proteins produced by the WJic or Wf allele were expressed on the surface of CMCs, but those of the Wn allele were not. When double heterozygous mice were produced between W and WJic and between W and Wn, both W/WJic and W/Wn mice lacked skin mast cells. W/WJic CMCs and W/Wn CMCs did not survive in the coculture with fibroblasts. W/WJic CMCs normally attached to fibroblasts, but W/Wn CMCs did not. The defect of W/Wn CMCs in the attachment was attributed to the deficient extracellular expression of the c-kit protein. The number of skin mast cells was compared among WJic/+, Wn/+, Wf/+, and Wf/Wf mice. Mast cells decreased in WJic/+ and Wf/Wf mice, but not in Wn/+ and Wf/+ mice. Although the Wn was a point mutation at the kinase domain, the biologic effect of the Wn was comparable with that of the W mutant allele, which produces truncated c-kit protein without the transmembrane domain. The weak phenotype of Wn/+ mice may be explained by the deficient extracellular expression of c-kit proteins produced by the Wn allele. When WJic/WJic, Wn/Wn, and Wf/Wf CMCs were stimulated by the recombinant c-kit ligand, autophosphorylation activity was observed only in Wf/Wf CMCs. This result was consistent with the weak biologic effect of the Wf mutant allele.