TRPM4 and TRPM5 Channels Share Crucial Amino Acid Residues for Ca²⁺ Sensitivity but Not Significance of PI(4,5)P₂.

ABSTRACT: Transient receptor potential melastatin member 4 (TRPM4) and 5 (TRPM5) channels are Ca²⁺-activated nonselective cation channels. Intracellular Ca²⁺ is the most important regulator for them to open, though PI(4,5)P₂, a membrane phosphoinositide, has been reported to regulate their Ca²⁺-sensitivities. We previously reported that negatively-charged amino acid residues near and in the TRP domain are necessary for the normal Ca²⁺ sensitivity of TRPM4. More recently, a cryo-electron microscopy structure of Ca²⁺-bound (but closed) TRPM4 was reported, proposing a Ca²⁺-binding site within an intracellular cavity formed by S2 and S3. Here, we examined the functional effects of mutations of the amino acid residues related to

SUBMITTER: Yamaguchi S 

PROVIDER: S-EPMC6514954 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature