Abstract
Ca2+ influx via plasma membrane Trp3 channels is proposed to be regulated by a reversible interaction with inositol trisphosphate receptor (IP3R) in the endoplasmic reticulum. Condensation of the cortical actin layer has been suggested to physically disrupt this interaction and inhibit Trp3-mediated Ca2+ influx. This study examines the effect of cytoskeletal reorganization on the localization and function of Trp3 and key Ca2+ signaling proteins. Calyculin-A treatment resulted in formation of condensed actin layer at the plasma membrane; internalization of Trp3, Gαq/11, phospholipase Cβ, and caveolin-1; and attenuation of 1-oleoyl-2-acetyl-sn-glycerol- and ATP-stimulated Sr2+ influx. Importantly, Trp3 and IP3R-3 remained co-localized inside the cell and were co-immunoprecipitated. Jasplakinolide also induced internalization of Trp3 and caveolin-1. Pretreatment of cells with cytochalasin D or staurosporine did not affect Trp3 but prevented calyculin-A-induced effects. Based on these data, we suggest that Trp3 is assembled in a caveolar Ca2+ signaling complex with IP3R, SERCA, Gαq/11, phospholipase Cβ, caveolin-1, and ezrin. Furthermore, our data demonstrate that conditions which stabilize cortical actin induce loss of Trp3 activity due to internalization of the Trp3-signaling complex, not disruption of IP 3R-Trp3 interaction. This suggests that localization of the Trp3-associated signaling complex, rather than Trp3-IP3R coupling, depends on the status of the actin cytoskeleton.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 42401-42408 |
| Number of pages | 8 |
| Journal | Journal of Biological Chemistry |
| Volume | 276 |
| Issue number | 45 |
| DOIs | |
| State | Published - Nov 9 2001 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Biochemistry
Cite this
Stabilization of Cortical Actin Induces Internalization of Transient Receptor Potential 3 (Trp3)-associated Caveolar Ca2+ Signaling Complex and Loss of Ca2+ Influx without Disruption of Trp3-Inositol Trisphosphate Receptor Association. / Lockwich, Timothy; Singh, Brij B; Liu, Xibao; Ambudkar, Indu S.
In: Journal of Biological Chemistry, Vol. 276, No. 45, 09.11.2001, p. 42401-42408.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Stabilization of Cortical Actin Induces Internalization of Transient Receptor Potential 3 (Trp3)-associated Caveolar Ca2+ Signaling Complex and Loss of Ca2+ Influx without Disruption of Trp3-Inositol Trisphosphate Receptor Association
AU - Lockwich, Timothy
AU - Singh, Brij B
AU - Liu, Xibao
AU - Ambudkar, Indu S.
PY - 2001/11/9
Y1 - 2001/11/9
N2 - Ca2+ influx via plasma membrane Trp3 channels is proposed to be regulated by a reversible interaction with inositol trisphosphate receptor (IP3R) in the endoplasmic reticulum. Condensation of the cortical actin layer has been suggested to physically disrupt this interaction and inhibit Trp3-mediated Ca2+ influx. This study examines the effect of cytoskeletal reorganization on the localization and function of Trp3 and key Ca2+ signaling proteins. Calyculin-A treatment resulted in formation of condensed actin layer at the plasma membrane; internalization of Trp3, Gαq/11, phospholipase Cβ, and caveolin-1; and attenuation of 1-oleoyl-2-acetyl-sn-glycerol- and ATP-stimulated Sr2+ influx. Importantly, Trp3 and IP3R-3 remained co-localized inside the cell and were co-immunoprecipitated. Jasplakinolide also induced internalization of Trp3 and caveolin-1. Pretreatment of cells with cytochalasin D or staurosporine did not affect Trp3 but prevented calyculin-A-induced effects. Based on these data, we suggest that Trp3 is assembled in a caveolar Ca2+ signaling complex with IP3R, SERCA, Gαq/11, phospholipase Cβ, caveolin-1, and ezrin. Furthermore, our data demonstrate that conditions which stabilize cortical actin induce loss of Trp3 activity due to internalization of the Trp3-signaling complex, not disruption of IP 3R-Trp3 interaction. This suggests that localization of the Trp3-associated signaling complex, rather than Trp3-IP3R coupling, depends on the status of the actin cytoskeleton.
AB - Ca2+ influx via plasma membrane Trp3 channels is proposed to be regulated by a reversible interaction with inositol trisphosphate receptor (IP3R) in the endoplasmic reticulum. Condensation of the cortical actin layer has been suggested to physically disrupt this interaction and inhibit Trp3-mediated Ca2+ influx. This study examines the effect of cytoskeletal reorganization on the localization and function of Trp3 and key Ca2+ signaling proteins. Calyculin-A treatment resulted in formation of condensed actin layer at the plasma membrane; internalization of Trp3, Gαq/11, phospholipase Cβ, and caveolin-1; and attenuation of 1-oleoyl-2-acetyl-sn-glycerol- and ATP-stimulated Sr2+ influx. Importantly, Trp3 and IP3R-3 remained co-localized inside the cell and were co-immunoprecipitated. Jasplakinolide also induced internalization of Trp3 and caveolin-1. Pretreatment of cells with cytochalasin D or staurosporine did not affect Trp3 but prevented calyculin-A-induced effects. Based on these data, we suggest that Trp3 is assembled in a caveolar Ca2+ signaling complex with IP3R, SERCA, Gαq/11, phospholipase Cβ, caveolin-1, and ezrin. Furthermore, our data demonstrate that conditions which stabilize cortical actin induce loss of Trp3 activity due to internalization of the Trp3-signaling complex, not disruption of IP 3R-Trp3 interaction. This suggests that localization of the Trp3-associated signaling complex, rather than Trp3-IP3R coupling, depends on the status of the actin cytoskeleton.
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U2 - 10.1074/jbc.M106956200
DO - 10.1074/jbc.M106956200
M3 - Article
C2 - 11524429
AN - SCOPUS:0035834716
VL - 276
SP - 42401
EP - 42408
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 45
ER -