Extent of intrinsic disorder and NMR chemical shift assignments of the distal N-termini from human TRPV1, TRPV2 and TRPV3 ion channels

Abstract

The mammalian Transient Receptor Potential Vanilloid (TRPV) channels are a family of six tetrameric ion channels localized at the plasma membrane. The group I members of the family, TRPV1 through TRPV4, are heat-activated and exhibit remarkable polymodality. The distal N-termini of group I TRPV channels contain large intrinsically disordered regions (IDRs), ranging from ~ 75 amino acids (TRPV2) to ~ 150 amino acids (TRPV4), the vast majority of which is invisible in the structural models published so far. These IDRs provide important binding sites for cytosolic partners, and their deletion is detrimental to channel activity and regulation. Recently, we reported the NMR backbone assignments of the distal TRPV4 N-terminus and noticed some discrepancies between the extent of disorder predicted solely based on protein sequence and from experimentally determined chemical shifts. Thus, for an analysis of the extent of disorder in the distal N-termini of all group I TRPV channels, we now report the NMR assignments for the human TRPV1, TRPV2 and TRPV3 IDRs.

Structure and dynamics of macrophage infectivity potentiator proteins from pathogenic bacteria and protozoans bound to fluorinated pipecolic acid inhibitors

“…In some cases, MIPs are equipped with additional domains, e.g. dimerization domains in L. pneumophila MIP (9,10).…”

“…A detailed structural and dynamic analysis of MIP homologs from different pathogen species, preferably both of bacterial and protozoan origin, with the same inhibitor scaffold would greatly benefit drug discovery efforts of pan-MIP inhibitors. Such information is currently limited to our study on [4.3.1]-bicyclic sulfonamides (9), but lacking for pipecolic acid-based inhibitors.…”

“…Here, we determined the crystal structures of B. pseudomallei MIP (BpMIP), which contains only the core PPIase domain and T. cruzi MIP (TcMIP), which features the PPIase domain and a free-standing -helix ('stalk'), in complex with fluorinated pipecolic acid inhibitors. No crystal structure for any of the LpMIP, which is a dimer composed of a PPIase domain, a stalk helix and a dimerization domain in each monomer (9) in complex with the inhibitors could be obtained. However, we derived a detailed comparison of the different inhibitor binding modes to the various MIP proteins from 1 H, 15 N solution NMR spectroscopy.…”

Crosstalk between regulatory elements in the disordered TRPV4 N-terminus modulates lipid-dependent channel activity

“…In some transient receptor potential (TRP) channels, IDRs make up more than half of the entire protein sequence 4 . Among the mammalian TRP vanilloid (TRPV) subfamily, TRPV4 has the largest N-terminal IDR, ranging from ~130 to ~150 amino acids in length depending on the species [4][5][6] . TRPV4 is a Ca 2+ -permeable plasma membrane channel that is widely expressed in human tissues.…”

“…For each sample, at least three technical replicates were measured. The tryptophan fluorescence wavelength at each lipid concentration was quantified by determining the average fluorescence wavelength using equation (6). The dissociation constants, Kd, of the protein liposome complexes were determined by plotting the changes in <λ> against the lipid concentration c and fitting the data with a Langmuir binding isotherm (equation ( 7)):…”