TY - JOUR
T1 - A molecular determinant of phosphoinositide affinity in mammalian TRPV channels
AU - Velisetty, Phanindra
AU - Borbiro, Istvan
AU - Kasimova, Marina A.
AU - Liu, Luyu
AU - Badheka, Doreen
AU - Carnevale, Vincenzo
AU - Rohacs, Tibor
N1 - Funding Information:
The human TRPV6 clone was provided by Dr. T. V. McDonald (Albert Einstein College of Medicine, New York, NY), the rat TRPV5 clone by Dr. Lucie Parent, (University of Montreal). The ciVSP clone was provided by Dr. Yasushi Okamura (Osaka University, Japan). This work was supported by NIH grants R01NS055159 and R01GM093290 to T.R.
PY - 2016/6/13
Y1 - 2016/6/13
N2 - Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2 ] is an important cofactor for ion channels. Affinity for this lipid is a major determinant of channel inhibition by depletion of PI(4,5)P2 upon phospholipase C (PLC) activation. Little is known about what determines PI(4,5)P2 affinity in mammalian ion channels. Here we report that two members of the Transient Receptor Potential Vanilloid (TRPV) ion channel family, TRPV5 and TRPV6 lack a positively charged residue in the TM4-TM5 loop that was shown to interact with PI(4,5)P2 in TRPV1, which shows high affinity for this lipid. When this positively charged residue was introduced to either TRPV6 or TRPV5, they displayed markedly higher affinities for PI(4,5)P2, and were largely resistant to inhibition by PI(4,5)P2 depletion. Furthermore, Ca2+ -induced inactivation of TRPV6 was essentially eliminated in the G488R mutant, showing the importance of PLC-mediated PI(4,5)P2 depletion in this process. Computational modeling shows that the introduced positive charge interacts with PI(4,5)P2 in TRPV6.
AB - Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2 ] is an important cofactor for ion channels. Affinity for this lipid is a major determinant of channel inhibition by depletion of PI(4,5)P2 upon phospholipase C (PLC) activation. Little is known about what determines PI(4,5)P2 affinity in mammalian ion channels. Here we report that two members of the Transient Receptor Potential Vanilloid (TRPV) ion channel family, TRPV5 and TRPV6 lack a positively charged residue in the TM4-TM5 loop that was shown to interact with PI(4,5)P2 in TRPV1, which shows high affinity for this lipid. When this positively charged residue was introduced to either TRPV6 or TRPV5, they displayed markedly higher affinities for PI(4,5)P2, and were largely resistant to inhibition by PI(4,5)P2 depletion. Furthermore, Ca2+ -induced inactivation of TRPV6 was essentially eliminated in the G488R mutant, showing the importance of PLC-mediated PI(4,5)P2 depletion in this process. Computational modeling shows that the introduced positive charge interacts with PI(4,5)P2 in TRPV6.
UR - https://www.scopus.com/pages/publications/84974779212
U2 - 10.1038/srep27652
DO - 10.1038/srep27652
M3 - Article
C2 - 27291418
AN - SCOPUS:84974779212
SN - 2045-2322
VL - 6
JO - Scientific Reports
JF - Scientific Reports
M1 - 27652
ER -