Transient receptor potential melastatin (TRPM) channels, a subfamily of the TRP superfamily, constitute a diverse group of ion channels involved in mediating crucial cellular processes like calcium homeostasis. These channels exhibit complex regulation, and one of the key regulatory mechanisms involves their interaction with calmodulin (CaM), a cytosol ubiquitous calcium-binding protein. The association between TRPM channels and CaM relies on the presence of specific CaM-binding domains in the channel structure. Upon CaM binding, the channel undergoes direct and/or allosteric structural changes and triggers down- or up-stream signaling pathways. According to current knowledge, ion channel members TRPM2, TRPM3, TRPM4, and TRPM6 are directly modulated by CaM, resulting in their activation or inhibition. This review specifically focuses on the interplay between TRPM channels and CaM and summarizes the current known effects of CaM interactions and modulations on TRPM channels in cellular physiology.

• Klíčová slova
• TRPM channels, calcium homeostasis, calmodulin, calmodulin binding site, regulation,
• MeSH
• kalmodulin * metabolismus   MeSH
• kationtové kanály TRPM * metabolismus   MeSH
• proteiny vázající vápník metabolismus   MeSH
• vápník metabolismus   MeSH
• vápníková signalizace MeSH
• vazba proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• kalmodulin * MeSH
• kationtové kanály TRPM * MeSH
• proteiny vázající vápník MeSH
• vápník MeSH

Molecular determinants of the binding of various endogenous modulators to transient receptor potential (TRP) channels are crucial for the understanding of necessary cellular pathways, as well as new paths for rational drug designs. The aim of this study was to characterise interactions between the TRP cation channel subfamily melastatin member 4 (TRPM4) and endogenous intracellular modulators-calcium-binding proteins (calmodulin (CaM) and S100A1) and phosphatidylinositol 4, 5-bisphosphate (PIP2). We have found binding epitopes at the N- and C-termini of TRPM4 shared by CaM, S100A1 and PIP2. The binding affinities of short peptides representing the binding epitopes of N- and C-termini were measured by means of fluorescence anisotropy (FA). The importance of representative basic amino acids and their combinations from both peptides for the binding of endogenous TRPM4 modulators was proved using point alanine-scanning mutagenesis. In silico protein-protein docking of both peptides to CaM and S100A1 and extensive molecular dynamics (MD) simulations enabled the description of key stabilising interactions at the atomic level. Recently solved cryo-Electron Microscopy (EM) structures made it possible to put our findings into the context of the entire TRPM4 channel and to deduce how the binding of these endogenous modulators could allosterically affect the gating of TRPM4. Moreover, both identified binding epitopes seem to be ideally positioned to mediate the involvement of TRPM4 in higher-order hetero-multimeric complexes with important physiological functions.

• Klíčová slova
• CaM, PIP2, S100A1, TRPM4 channel, binding epitope, docking, fluorescence anisotropy, molecular dynamics simulations,
• MeSH
• akvaporiny chemie   metabolismus   MeSH
• interakční proteinové domény a motivy * MeSH
• kalmodulin chemie   metabolismus   MeSH
• kationtové kanály TRPM chemie   metabolismus   MeSH
• kinetika MeSH
• konformace proteinů MeSH
• lidé MeSH
• molekulární modely MeSH
• multiproteinové komplexy chemie   metabolismus   MeSH
• peptidové fragmenty MeSH
• proteiny S100 chemie   metabolismus   MeSH
• sekvence aminokyselin MeSH
• vazba proteinů MeSH
• vazebná místa * MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• akvaporiny MeSH
• kalmodulin MeSH
• kationtové kanály TRPM MeSH
• multiproteinové komplexy MeSH
• peptidové fragmenty MeSH
• proteiny S100 MeSH
• S100A1 protein MeSH Prohlížeč
• TRPM4 protein, human MeSH Prohlížeč