TRPM6 kinase activity regulates TRPM7 trafficking and inhibits cellular growth under hypomagnesic conditions.
TRPM6 kinase activity regulates TRPM7 trafficking and inhibits cellular growth under hypomagnesic conditions.
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DOI：
10.1007/s00018-014-1647-7
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发表时间：
2014-12
影响因子：
8
通讯作者：
Schmitz, Carsten
中科院分区：
文献类型：
--
作者：
Brandao, Katherine;Deason-Towne, Francina;Zhao, Xiaoyun;Perraud, Anne-Laure;Schmitz, Carsten
通道激酶TRPM 6和TRPM 7都是离子通道的melastatin相关瞬时受体电位（TRPM）亚家族的成员，并且是唯一已知的离子通道孔与激酶结构域的融合体。TRPM 6和TRPM 7通过异聚化在质膜上形成功能性四聚体通道复合物。TRPM 6先前显示交叉磷酸化TRPM 7上的苏氨酸残基，但反之亦然。遗传研究表明，TRPM 6和TRPM 7履行非冗余功能，并且每个通道都对Mg 2+稳态的调节做出独特贡献。尽管有迹象表明TRPM 6和TRPM 7可以影响彼此的细胞分布和活性，但对这两种通道激酶之间的功能关系知之甚少。在本研究中，我们研究了TRPM 6激酶活性如何影响TRPM 7丝氨酸磷酸化，细胞内运输，TRPM 7的细胞表面表达，以及Mg 2+依赖的细胞生长。我们发现TRPM 7丝氨酸磷酸化通过TRPM 6激酶，但没有TRPM 6丝氨酸磷酸化通过TRPM 7激酶。在具有完整激酶活性的TRPM 6存在的情况下，HEK-293上皮肾细胞和DT 40 B细胞中TRPM 7的细胞内运输发生了改变，与细胞外Mg 2+的可用性无关，但TRPM 6/7表面标记实验表明TRPM 6/7通道的水平相当在质膜上。此外，在TRPM 7缺陷型DT 40 B细胞中使用互补方法，我们证明了野生型TRPM 6在共表达TRPM 6和TRPM 7的细胞中在低镁细胞培养条件下抑制细胞生长，然而TRPM 6激酶死亡突变体的共表达没有影响-在TRPM 6/7共表达的HEK-293细胞中也观察到类似的表型。我们的研究结果提供了关于TRPM 6和TRPM 7之间的异聚体形成如何影响这些离子通道的生物活性的第一条线索。我们表明，TRPM 6调节TRPM 7的细胞内运输和TRPM 7依赖的细胞生长。所有这些作用都依赖于活性TRPM 6激酶结构域的存在。失调的Mg 2+稳态导致或加剧许多病理。由于TRPM 6和TRPM 7在许多细胞类型中同时表达，因此了解它们的关系如何影响Mg 2+摄取的调节是重要的知识。
The channel kinases TRPM6 and TRPM7 are both members of the melastatin related transient receptor potential (TRPM) subfamily of ion channels and the only known fusions of an ion channel pore with a kinase domain. TRPM6 and TRPM7 form functional, tetrameric channel complexes at the plasma membrane by heteromerization. TRPM6 was previously shown to cross-phosphorylate TRPM7 on threonine residues, but not vice versa. Genetic studies demonstrated that TRPM6 and TRPM7 fulfill non-redundant functions, and that each channel contributes uniquely to the regulation of Mg2+ homeostasis. Although there are indications that TRPM6 and TRPM7 can influence each other’s cellular distribution and activity, little is known about the functional relationship between these two channel-kinases. In the present study, we examined how TRPM6 kinase activity influences TRPM7 serine phosphorylation, intracellular trafficking, and cell surface expression of TRPM7, as well as Mg2+-dependent cellular growth. We found TRPM7 serine phosphorylation via the TRPM6 kinase, but no TRPM6 serine phosphorylation via the TRPM7 kinase. Intracellular trafficking of TRPM7 was altered in HEK-293 epithelial kidney cells and DT40 B cells in the presence of TRPM6 with intact kinase activity, independently of the availability of extracellular Mg2+, but TRPM6/7 surface labeling experiments indicate comparable levels of the TRPM6/7 channels at the plasma membrane. Furthermore, using a complementation approach in TRPM7-deficient DT40 B-cells, we demonstrated that wildtype TRPM6 inhibited cell growth under hypomagnesic cell culture conditions in cells co-expressing TRPM6 and TRPM7, however co-expression of a TRPM6 kinase dead mutant had no effect – a similar phenotype was also observed in TRPM6/7 co-expressing HEK-293 cells. Our results provide first clues about how heteromer formation between TRPM6 and TRPM7 influences the biological activity of these ion channels. We show that TRPM6 regulates TRPM7 intracellular trafficking and TRPM7 dependent cell growth. All these effects are dependent upon the presence of an active TRPM6 kinase domain. Dysregulated Mg2+-homeostasis causes or exacerbates many pathologies. As TRPM6 and TRPM7 are expressed simultaneously in numerous cell types, understanding how their relationship impacts regulation of Mg2+-uptake is thus important knowledge.
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影响因子：
3.8
作者：
Li, Mingjiang;Jiang, Jianmin;Yue, Lixia
通讯作者：
Yue, Lixia
影响因子：
4
作者：
Cayouette, Sylvie;Boulay, Guylain
通讯作者：
Boulay, Guylain
影响因子：
64.8
作者：
Li, Feng-Yen;Chaigne-Delalande, Benjamin;Kanellopoulou, Chrysi;Davis, Jeremiah C.;Matthews, Helen F.;Douek, Daniel C.;Cohen, Jeffrey I.;Uzel, Gulbu;Su, Helen C.;Lenardo, Michael J.
通讯作者：
Lenardo, Michael J.
影响因子：
3.5
作者：
Deason-Towne, Francina;Perraud, Anne-Laure;Schmitz, Carsten
通讯作者：
Schmitz, Carsten
影响因子：
11.8
作者：
Desai, Bimal N.;Krapivinsky, Grigory;Navarro, Betsy;Krapivinsky, Luba;Carter, Brett C.;Febvay, Sebastien;Delling, Markus;Penumaka, Anirudh;Ramsey, I. Scott;Manasian, Yunona;Clapham, David E.
通讯作者：
Clapham, David E.