Genomic organization and functional analysis of murine PKD2L1
Genomic organization and functional analysis of murine PKD2L1
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DOI：
10.1074/jbc.m411496200
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发表时间：
2005-02-18
影响因子：
4.8
通讯作者：
Iijima, T
中科院分区：
文献类型：
--
作者：
Murakami, M;Ohba, T;Iijima, T
编码多囊蛋白1或2的基因突变导致多囊肾病（PKD）。在这里，我们报告了人类多囊蛋白-2L1（PKD 2L 1）的小鼠直系同源物的基因组组织和功能表达。鼠PY.D2L1基因在染色体19 C3中包含15个外显子。PKD 2L 1与多囊蛋白-1（PKD 1）共表达导致PKD 2L 1通道在细胞表面上表达，而单独表达的PKD 2L 1保留在内质网（ER）内。这表明PKD 1和PKD 2L 1之间的相互作用对PKD 2L 1的运输和通道形成至关重要。在胞质尾的P`KD 2L 1的缺失分析表明，卷曲螺旋结构域是重要的贩运PKD 1。两个新鉴定的ER滞留信号样氨基酸序列内的突变导致PKD 2L 1在细胞表面表达。这表明卷曲螺旋结构域负责将PKD 2L 1保留在ER内。使用钙成像对HEK 293细胞中表达的鼠P`KD 2L 1进行功能分析。PKD 1和P`KD 2L 1的共表达导致功能性阳离子通道的形成，这些通道通过低渗刺激打开，而单独表达时两种分子都不形成功能性通道。我们得出结论，PKD 2L 1通过与PKD 1相互作用在质膜上形成功能性阳离子通道。这些发现提出了PKD 2L 1代表负责PKD的第三个遗传位点的可能性。
Mutations in genes that encode polycystins 1 or 2 cause polycystic kidney disease (PKD). Here, we report the genomic organization and functional expression of murine orthologue of human polycystin-2L1 (PKD2L1). The murine PY.D2L1 gene comprises 15 exons in chromosome 19C3. Coexpression of PKD2L1 together with polycystin-1 (PKD1) resulted in the expression of PKD2L1 channels on the cell surface, whereas PKD2L1 expressed alone was retained within the endoplasmic reticulum (ER). This suggested that interaction between PKD1 and PKD2L1 is essential for PKD2L1 trafficking and channel formation. Deletion analysis at the cytoplasmic tail of P`KD2L1 revealed that the coiled-coil domain was important for trafficking by PKD1. Mutagenesis within two newly identified ER retention signal-like amino acid sequences caused PKD2L1 to be expressed at the cell surface. This indicated that the coiled-coil domain was responsible for retaining PKD2L1 within the ER. Functional analysis of murine P`KD2L1 expressed in HEK 293 cells was undertaken using calcium imaging. Coexpression of PKD1 and P`KD2L1 resulted in the formation of functional cation channels that were opened by hypo-osmotic stimulation, whereas neither molecule formed functional channels when expressed alone. We conclude that PKD2L1 forms functional cation channels on the plasma membrane by interacting with PKD1. These findings raise the possibility that PKD2L1 represents the third genetic locus that is responsible for PKD.