TY - JOUR
T1 - STIM1-dependent and STIM1-independent function of Transient Receptor Potential Canonical (TRPC) channels tunes their store-operated mode
AU - Lee, Kyu Pil
AU - Yuan, Joseph P.
AU - So, Insuk
AU - Worley, Paul F.
AU - Muallem, Shmuel
PY - 2010/12/3
Y1 - 2010/12/3
N2 - Ca2+ influx by store-operated Ca2+ channels is a key component of the receptor-evoked Ca2+ signal. In all cells examined, transient receptor potential canonical (TRPC) channels mediate a significant portion of the receptor-stimulated Ca2+ influx. Recent studies have revealed how STIM1 activates TRPC1 in response to store depletion; however, the role of STIM1 in TRPC channel activation by receptor stimulation is not fully understood. Here, we established mutants of TRPC channels that could not be activated by STIM1 but were activated by the "charge-swap" mutant STIM1(K684E,K685E). Significantly, WT but not mutant TRPC channels were inhibited by scavenging STIM1 with Orai1(R91W), indicating the STIM1 dependence and independence of WT and mutant TRPC channels, respectively. Importantly, mutant TRPC channels were robustly activated by receptor stimulation. Moreover, STIM1 and STIM1(K684E,K685E) reciprocally affected receptor-activated WT and mutant TRPC channels. Together, these findings indicate that TRPC channels can function as STIM1-dependent and STIM1-independent channels, which increases the versatility of TRPC channel function and their role in receptor-stimulated Ca2+ influx.
AB - Ca2+ influx by store-operated Ca2+ channels is a key component of the receptor-evoked Ca2+ signal. In all cells examined, transient receptor potential canonical (TRPC) channels mediate a significant portion of the receptor-stimulated Ca2+ influx. Recent studies have revealed how STIM1 activates TRPC1 in response to store depletion; however, the role of STIM1 in TRPC channel activation by receptor stimulation is not fully understood. Here, we established mutants of TRPC channels that could not be activated by STIM1 but were activated by the "charge-swap" mutant STIM1(K684E,K685E). Significantly, WT but not mutant TRPC channels were inhibited by scavenging STIM1 with Orai1(R91W), indicating the STIM1 dependence and independence of WT and mutant TRPC channels, respectively. Importantly, mutant TRPC channels were robustly activated by receptor stimulation. Moreover, STIM1 and STIM1(K684E,K685E) reciprocally affected receptor-activated WT and mutant TRPC channels. Together, these findings indicate that TRPC channels can function as STIM1-dependent and STIM1-independent channels, which increases the versatility of TRPC channel function and their role in receptor-stimulated Ca2+ influx.
UR - http://www.scopus.com/inward/record.url?scp=78649674863&partnerID=8YFLogxK
U2 - 10.1074/jbc.M110.155036
DO - 10.1074/jbc.M110.155036
M3 - Article
C2 - 20926378
AN - SCOPUS:78649674863
SN - 0021-9258
VL - 285
SP - 38666
EP - 38673
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 49
ER -