Differential evolution and expression of murine peroxisomal membrane protein genes.
Differential evolution and expression of murine peroxisomal membrane protein genes.
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DOI：
10.1006/bmme.1995.1027
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发表时间：
1995-06
期刊：
影响因子：
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通讯作者：
D. Bryant;G. N. Wilson
中科院分区：
文献类型：
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作者：
D. Bryant;G. N. Wilson
编码70和22-kDa过氧化物酶体膜蛋白（PMP）的基因片段已在小鼠中进行了表征，并与其他过氧化物酶体蛋白在进化和表达方面进行了比较。小鼠PMP 22基因序列预测A16 G和I136 V的取代，同意与溴化氰裂解分析所定义的，提供了额外的证据，该基因编码的主要22 kDa的膜蛋白可视化SDS-聚丙烯酰胺电泳。哺乳动物的PMP 22基因表现出比PMP 35（0.14%）、PMP 70（0.07%）或过氧化氢酶基因（0.13%）高的进化率（每百万年0.17%的氨基酸替换）。基于Southern分析，PMP 70基因区域在整个脊椎动物门中是保守的，而PMP 22序列仅在啮齿动物中检测到。氨基酸取代聚集在PMP 22和PMP 70基因中，并且它们的模式支持来自亲水性概况的膜拓扑结构。北方印迹分析鉴定了几种啮齿动物组织中4.6 kb（PMP 70）、1.4 kb（PMP 22）和2.3 kb（过氧化氢酶）的单个mRNA。定量或竞争性RT-PCR检测过氧化氢酶mRNA分子的数量是脑、肝和肾中PMP mRNA分子的2 - 3倍;在这些组织中，PMP 22和PMP 35 mRNA的丰度是PMP 70 mRNA的2倍。稳态水平的PMP 22 mRNA在啮齿类动物的肝脏，肾脏，脊髓和十二指肠的最高水平，结肠，肾上腺，胸腺和脾脏的水平较低。我们的结论是，PMP基因表现出独立的进化速率和组织调控，这表明它们在过氧化物酶体生物合成和组织分化中具有独特的作用。
Gene segments encoding the 70 and 22-kDa peroxisomal membrane proteins (PMP) have been characterized in mice and compared with other peroxisomal proteins in terms of evolution and expression. The mouse PMP22 gene sequence predicts A16G and I136V substitutions that agree with those defined by cyanogen bromide cleavage analysis, providing additional evidence that this gene encodes the major 22-kDa membrane protein visualized by SDS-polyacrylamide electrophoresis. Mammalian PMP22 genes exhibit high evolutionary rates (0.17% amino acid substitution per million years) than PMP35 (0.14%), PMP70 (0.07%), or catalase genes (0.13%). PMP70 gene regions are conserved throughout vertebrate phylas based on Southern analysis, while PMP22 sequences were only detected in rodents. Amino acid substitutions are clustered in both PMP22 and PMP70 genes, and their pattern supports membrane topologies derived from hydropathy profiles. Northern blot analysis identifies single mRNAs of 4.6 kb (PMP70), 1.4 kb (PMP22), and 2.3 kb (catalase) in several rodent tissues. Quantitative or competitive RT-PCR assays detected two- to three-fold greater numbers of catalase mRNA molecules relative to PMP mRNA molecules in brain, liver, and kidney; PMP22 and PMP35 mRNAs were two-fold more abundant than PMP70 mRNA in these tissues. Steady-state levels of PMP22 mRNA were highest in rodent liver kidney, spinal cord, and duodenum with low levels in colon, adrenal, thymus, and spleen. We conclude that PMP genes exhibit independent evolutionary rates and tissue regulation, suggesting that they have unique roles in peroxisome biogenesis and tissue differentiation.