Depletion of plasma membrane–associated phosphoinositides mimics inhibition of TRPM7 channels by cytosolic Mg2+, spermine, and pH

Zhelay, Tetyana; Wieczerzak, Krystyna Blanka; Beesetty, Pavani; Alter, Gerald M.; Matsushita, Masayuki; Kozak, J. Ashot

doi:10.1074/jbc.ra118.004066

Cited by 20 publications

(56 citation statements)

References 76 publications

(139 reference statements)

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“…Several reports indicate that activation of phospholipase C (PLC) induces Ca 2+ influx via TRPM7 in intact cells (Langeslag et al ; Qian et al ). There are contradicting reports showing that TRPM7 is inactivated by G αq ‐coupled receptor stimulation via the PLC‐mediating depletion of phosphatidylinositol 4,5‐bisphosphates (PIP 2 ) which is necessary for TRPM7 channel activity (Runnels et al ; Kozak et al ; Gwanyanya et al ; Bates‐Withers et al ; Zhelay et al ). Therefore, the physiological stimuli that activate PLC in adipocytes might increase or decrease [Ca 2+ ] i by activation or inactivation of TRPM7.…”

Section: Discussionmentioning

confidence: 96%

Functional expression of TRPM7 as a Ca²⁺influx pathway in adipocytes

et al. 2019

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In adipocytes, intracellular Ca2+ and Mg2+ modulates physiological functions, such as insulin action and the secretion of adipokines. TRPM7 is a Ca2+/Mg2+‐permeable non‐selective cation channel. TRPM7 mRNA is highly expressed in adipose tissue, however, its functional expression in adipocytes remains to be elucidated. In this study, we demonstrated for the first time that TRPM7 was functionally expressed in both freshly isolated white adipocytes and in 3T3‐L1 adipocytes differentiated from a 3T3‐L1 pre‐adipocyte cell line by whole‐cell patch‐clamp recordings. Consistent with known properties of TRPM7 current, the current in adipocytes was activated by the elimination of extracellular divalent cations and the reduction of intracellular free Mg2+ concentrations, and was inhibited by the TRPM7 inhibitors, 2‐aminoethyl diphenylborinate (2‐APB), hydrogen peroxide (H2O2), N‐methyl maleimide (NMM), NS8593, and 2‐amino‐2‐[2‐(4‐octylphenyl)ethyl]‐1,3‐propanediol (FTY720). Treatment with small‐interfering (si) RNA targeting TRPM7 resulted in a reduction in the current to 23 ± 7% of nontargeting siRNA‐treated adipocytes. Moreover a TRPM7 activator, naltriben, increased the TRPM7‐like current and [Ca2+]i in 3T3‐L1 adipocytes but not in TRPM7‐knockdown adipocytes. These findings indicate that TRPM7 is functionally expressed, and plays a role as a Ca2+ influx pathway in adipocytes.

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Section: Discussionmentioning

confidence: 96%

Functional expression of TRPM7 as a Ca²⁺influx pathway in adipocytes

et al. 2019

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“…activity (Miller et al, 2015;Nowicka-Bauer and Szymczak-Cendlak, 2021) and sperm tail VSP protein. The level of phosphorylation varies (Zhelay et al, 2018). Zhou et al (2015) found that total sperm motility and progressive motility were higher at pH 7.2 and 8.2 than at pH 5.2 and 6.2.…”

Section: Discussionmentioning

confidence: 99%

Effects of Diluent pH on Enrichment and Performance of Dairy Goat X/Y Sperm

Huang

et al. 2021

Front. Cell Dev. Biol.

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In this paper, on the basis of the differences in the hydrogen ion concentration (pH) of the diluent dairy goat semen on X/Y sperm motility, an X/Y sperm enrichment study was conducted to establish a simple and effective method for gender control in dairy goats. Dairy goat semen was diluted using different pH dilutions and was incubated. Then, the X/Y sperm ratio in the isolated upper sperm was determined using the double TaqMan qPCR method. The internal pH change pattern of sperm cells at different pH dilutions was measured using BCECF-AM probe, and the functional parameters of the isolated sperm were tested with the corresponding kit. Next, an in vitro fertilization test was conducted using isolated spermatozoa and oocytes to determine their fertilization rates, the percentages of female embryos, and the expression of genes related to developing potentially fertilized embryos. Results showed that the percentages of the X sperm cells in the upper sperm layer were 67.24% ± 2.61% at sperm dilution pH of 6.2 and 30.45% ± 1.03% at sperm dilution pH of 7.4, which was significantly different from 52.35% ± 1.72% of the control group (pH 6.8) (P < 0.01). Results also showed that there is a relationship between the external pHo and internal pHi of sperm cells. Furthermore, the percentages of female embryos after the in vitro fertilization of the isolated upper sperm with mature oocytes at pH 6.2 and 7.4 were 66.67% ± 0.05 and 29.73% ± 0.04%, respectively, compared with 48.57% ± 0.02% in the control group (pH 6.8). Highly significant differences occurred between groups (P < 0.01). Additionally, no significant difference was observed during the expression of genes related to embryonic development between the blastocysts formed from sperm isolated by changing the pH of the diluent and the control sperm (P > 0.05). Therefore, this study successfully established a simple and effective method for enriched X/Y sperms from dairy goats, which is important for regulating the desired sex progeny during dairy goat breeding and for guiding dairy goat production.

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“…H 2 O 2 shifted the [Mg 2+ ] i -dependent inhibition curves to lower concentrations with a single IC 50 of 3.4 µM (Figure 1D). It has been reported that mTRPM7-S1107E mutant is insensitive to [Mg 2+ ] i (Hofmann et al, 2014; Zhelay et al, 2018). Consistently, the spontaneous current activation after break-in was not observed in mTRPM7-S1107E mutant in whole-cell recordings (Figure 1E).…”

Section: Resultsmentioning

confidence: 99%

Zinc-binding motif acts as an oxidative stress sensor to regulate TRPM7 channel activity

Inoue¹,

Murayama

Kobayashi

et al. 2020

Preprint

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TRPM7 channel activity is negatively regulated by intracellular Mg2+. We previously reported that TRPM7 was inhibited by oxidative stress due to an enhancement of the inhibition by intracellular Mg2+. In the present study, we aimed to clarify the precise mechanism underlying the TRPM7 inhibition by oxidative stress induced by hydrogen peroxide (H2O2). Site-directed mutagenesis on full-length TRPM7 revealed that none of the cysteines other than C1809 and C1813 within the zinc-binding motif of the TRPM7 kinase domain was involved in the H2O2-induced TRPM7 inhibition. When C1809 or C1813 was mutated, full-length TRPM7 failed to be expressed on the plasmamembrane. We therefore developed a novel approach in which the full-length TRPM7 is functionally reconstituted by co-expressing the TRPM7 channel domain (M7cd) and the TRPM7 kinase domain (M7kd) as separate individual proteins in HEK293 cells. When M7cd was expressed alone, the current was inhibited by intracellular Mg2+ stronger than in full-length TRPM7. Co-expression of M7cd and M7kd attenuated the current inhibition by intracellular Mg2+, and the current was sensitive to oxidative stress, indicating a successful reconstitution of a full-length TRPM7-like current. A similar current reconstitution was observed when M7cd co-expressed with the kinase inactive mutant M7kd-K1645R. Thus, it was suggested that the kinase activity might not be essential for the reconstitution. Co-expression of M7cd and M7kd carrying a mutation at C1809 or C1813 failed to restore the full-length TRPM7-like current. No reconstitution was also observed with M7kd carrying a mutation at H1750 and H1807, which are involved in the zinc-binding motif formation together with C1809 and C1813. These data suggest that the zinc-binding motif is essential for the intracellular Mg2+-dependent regulation of the TRPM7 channel activity by M7kd, and the cysteines in the zinc-binding motif might play a role in the oxidative stress response of TRPM7.

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Depletion of plasma membrane–associated phosphoinositides mimics inhibition of TRPM7 channels by cytosolic Mg2+, spermine, and pH

Cited by 20 publications

References 76 publications

Functional expression of TRPM7 as a Ca²⁺influx pathway in adipocytes

Functional expression of TRPM7 as a Ca²⁺influx pathway in adipocytes

Effects of Diluent pH on Enrichment and Performance of Dairy Goat X/Y Sperm

Zinc-binding motif acts as an oxidative stress sensor to regulate TRPM7 channel activity

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Depletion of plasma membrane–associated phosphoinositides mimics inhibition of TRPM7 channels by cytosolic Mg2+, spermine, and pH

Cited by 20 publications

References 76 publications

Functional expression of TRPM7 as a Ca2+influx pathway in adipocytes

Functional expression of TRPM7 as a Ca2+influx pathway in adipocytes

Effects of Diluent pH on Enrichment and Performance of Dairy Goat X/Y Sperm

Zinc-binding motif acts as an oxidative stress sensor to regulate TRPM7 channel activity

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Product

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Functional expression of TRPM7 as a Ca²⁺influx pathway in adipocytes

Functional expression of TRPM7 as a Ca²⁺influx pathway in adipocytes