Ca2+-independent phospholipase A2-dependent gating of TRPM8 by lysophospholipids.
TRPM8 represents an ion channel activated by cold temperatures and cooling agents, such as menthol, that underlies the cold-induced excitation of sensory neurons. Interestingly, the only human tissue outside the peripheral nervous system, in which the expression of TRPM8 transcripts has been detected at high levels, is the prostate, a tissue not exposed to any essential temperature variations. Here we show that the TRPM8 cloned from human prostate and heterologously expressed in HEK-293 cells is regulated by the Ca(2+)-independent phospholipase A(2) (iPLA(2)) signaling pathway with its end products, lysophospholipids (LPLs), acting as its endogenous ligands. LPLs induce prominent prolongation of TRPM8 channel openings that are hardly detectable with other stimuli (e.g. cold, menthol, and depolarization) and that account for more than 90% of the total channel open time. Down-regulation of iPLA(2) resulted in a strong inhibition of TRPM8-mediated functional responses and abolished channel activation. The action of LPLs on TRPM8 channels involved either changes in the local lipid bilayer tension or interaction with the critical determinant(s) in the transmembrane channel core. Based on this, we propose a novel concept of TRPM8 regulation with the involvement of iPLA(2) stimulation. This mechanism employs chemical rather than physical (temperature change) signaling and thus may be the main regulator of TRPM8 activation in organs not exposed to any essential temperature variations, as in the prostate gland.
Vanden Abeele
Fabien
F
INSERM U800, Equipe Labellisée par la Ligue contre le Cancer, Villeneuve d'Ascq F-59650, France and Universite Lille 1, Villeneuve d'Ascq F-59650, France.
Zholos
Alexander
A
Bidaux
Gabriel
G
Shuba
Yaroslav
Y
Thebault
Stephanie
S
Beck
Benjamin
B
Flourakis
Matthieu
M
Panchin
Yuri
Y
Skryma
Roman
R
Prevarskaya
Natalia
N
D002118:Calcium / Q000378:metabolism / Q000502:physiology*; D015220:Calcium Channels / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000201:enzymology / Q000378:metabolism; D054522:Group VI Phospholipases A2; D006801:Humans; D015640:Ion Channel Gating / Q000502:physiology*; D008024:Ligands; D008246:Lysophospholipids / Q000378:metabolism / Q000502:physiology*; D010741:Phospholipases A / Q000378:metabolism / Q000502:physiology*; D054467:Phospholipases A2; D050053:TRPM Cation Channels / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*
D015220:Calcium Channels; D008024:Ligands; D008246:Lysophospholipids; D050053:TRPM Cation Channels; C425966:TRPM8 protein, human; D010741:Phospholipases A; D054522:Group VI Phospholipases A2; C516475:PLA2G6 protein, human; D054467:Phospholipases A2; D002118:Calcium