Targeted disruption of the β adducin gene (Add2) causes red blood cell spherocytosis in mice
Targeted disruption of the β adducin gene (Add2) causes red blood cell spherocytosis in mice
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DOI：
10.1073/pnas.96.19.10717
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发表时间：
1999-09-14
影响因子：
11.1
通讯作者：
Peters, LL
中科院分区：
文献类型：
--
作者：
Gilligan, DM;Lozovatsky, L;Peters, LL
内收蛋白是由三个基因（α、β、γ）编码的细胞骨架蛋白家族。在基因表达的综合分析中，我们显示了 α-和 γ-内收蛋白的普遍表达，与 β-内收蛋白的有限表达相反，β-内收蛋白在大脑和造血组织（人类骨髓、小鼠脾脏）中高水平表达。为了阐明内收蛋白在体内的作用，我们通过基因打靶，删除外显子 9-13，创建了 β-内收蛋白缺失小鼠。β-内收蛋白的前 8 个外显子和脾脏中 neo 盒的一部分产生了 55-kDa 嵌合多肽，但在外周红细胞或大脑中未检测到。与野生型相比，β-内收蛋白缺失的红细胞渗透脆弱、呈球形且脱水，类似于遗传性球形红细胞增多症患者的红细胞。红细胞中缺乏 β-内收蛋白导致 α-内收蛋白的膜掺入减少（正常的 30%），并意外地促使 γ-内收蛋白掺入红细胞膜骨架增加 5 倍。这项研究证明了内收蛋白对体内红细胞膜稳定性的重要性。
Adducins are a family of cytoskeleton proteins encoded by three genes (alpha, beta, gamma), In a comprehensive assay of gene expression, we show the ubiquitous expression of alpha- and gamma-adducins in contrast to the restricted expression of beta-adducin, beta-adducin is expressed at high levels in brain and hematopoietic tissues (bone marrow in humans, spleen in mice). To elucidate adducin's role in vivo, we created beta-adducin null mice by gene targeting, deleting exons 9-13, A 55-kDa chimeric polypeptide is produced from the first eight exons of beta-adducin and part of the neo cassette in spleen but is not detected in peripheral RBCs or brain. beta-adducin null RBCs are osmotically fragile, spherocytic, and dehydrated compared with the wild type, resembling RBCs from patients with hereditary spherocytosis, The lack of beta-adducin in RBCs leads to decreased membrane incorporation of alpha-adducin (30% of normal) and unexpectedly promotes a 5-fold increase in gamma-adducin incorporation into the RBC membrane skeleton. This study demonstrates adducin's importance to RBC membrane stability in vivo.