The DC splice-variant of TRPM2 is thehypertonicity-induced cation channel(HICC) in HeLa cells, and the ecto-enzymeCD38 mediates its activation
The DC splice-variant of TRPM2 is thehypertonicity-induced cation channel(HICC) in HeLa cells, and the ecto-enzymeCD38 mediates its activation
复制标题
TRPM2的DC剪接变体是HeLa细胞中的高渗诱导的阳离子通道(HICC)，胞外酶CD38介导其激活
DOI：
10.1113/jphysiol.2011.220947
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Okada Y & Wehner F.
中科院分区：
文献类型：
--
作者：
Numata T;Sato K;Christmann J;Marx R;Mori Y;Okada Y & Wehner F.
高渗诱导的阳离子通道（hypertonicity-induced cationchannels，简称CMC）是增殖和凋亡的关键参与者，但它们的分子身份仍然难以捉摸。我们报道了在HeLa细胞中，细胞内的腺苷二磷酸核糖（ADPr）和环ADPr（cADPr）作为TRPM 2阳离子通道的激活剂，引起的电流与渗透性激活的CCRCs相同。siRNA介导的TRPM 2和CD 38（作为ADPr和cADPr的假定来源）表达的沉默抑制了HICC和核苷酸诱导的电流以及细胞的渗透容积反应。细胞内cADPr和细胞外核苷酸应用的定量显示，ADPr和cADPr的外向梯度而非细胞内活性是TRPM 2的触发因素。·TRPM 2的克隆鉴定出ΔC-剪接变体是HICC的分子相关物，这得到了Ca 2+选择性定量的支持。·免疫沉淀和FRET/FLIM分析揭示了TRPM 2和CD 38的相互作用，我们提出了通过CD 38的转运相关核苷酸输出作为TRPM 2激活的新机制。
Key points•Hypertonicity‐induced cation channels (HICCs) are key players in proliferation and apoptosis but their molecular identity has remained elusive.•We report that in HeLa cells, intracellular adenosine diphosphate ribose (ADPr) and cyclic ADPr (cADPr), as activators of TRPM2 cation channels, elicited currents that are identical to the osmotic activation of HICCs.•siRNA‐mediated silencing of the expression of TRPM2 and CD38 (as the supposed source of ADPr and cADPr) inhibited HICC and nucleotide‐induced currents and the osmotic volume response of cells.•Quantification of intracellular cADPr and extracellular application of nucleotides revealed that the outwardly directed gradient rather than the intracellular activity of ADPr and cADPr is the triggering factor for TRPM2.•Cloning of TRPM2 identified the ΔC‐splice variant as the molecular correlate of the HICC, which was supported by quantification of Ca2+selectivity.•Immunoprecipation and FRET/FLIM assays revealed the interaction of TRPM2 and CD38 and we propose a transport‐related nucleotide export via CD38 as a novel mechanism of TRPM2 activation.