Abstract
In non-excitable cells, receptor-activated Ca2+ signalling comprises initial transient responses followed by a Ca2+ entry-dependent sustained and/or oscillatory phase. Here, we describe the molecular mechanism underlying the second phase linked to signal amplification. An in vivo inositol 1,4,5-trisphosphate (IP3) sensor revealed that in B lymphocytes, receptor-activated and store-operated Ca2+ entry greatly enhanced IP3 production, which terminated in phospholipase Cγ2 (PLCγ2)-deficient cells. Association between receptor-activated TRPC3 Ca2+ channels and PLCγ2, which cooperate in potentiating Ca2+ responses, was demonstrated by co-immunoprecipitation. PLCγ2-deficient cells displayed diminished Ca2+ entry-induced Ca2+ responses. However, this defect was canceled by suppressing IP3-induced Ca2+ release, implying that IP3 and IP3 receptors mediate the second Ca2+ phase. Furthermore, confocal visualization of PLCγ2 mutants demonstrated that Ca2+ entry evoked a C2 domain-mediated PLCγ2 translocation towards the plasma membrane in a lipase-independent manner to activate PLCγ2. Strikingly, Ca2+ entry-activated PLCγ2 maintained Ca2+ oscillation and extracellular signal-regulated kinase activation downstream of protein kinase C. We suggest that coupling of Ca 2+ entry with PLCγ2 translocation and activation controls the amplification and co-ordination of receptor signalling.
| Original language | English |
|---|---|
| Pages (from-to) | 4677-4688 |
| Number of pages | 12 |
| Journal | EMBO Journal |
| Volume | 22 |
| Issue number | 18 |
| DOIs | |
| Publication status | Published - Sep 15 2003 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Neuroscience(all)
- Molecular Biology
- Biochemistry, Genetics and Molecular Biology(all)
- Immunology and Microbiology(all)
Cite this
Amplification of receptor signalling by Ca2+ entry-mediated translocation and activation of PLCγ2 in B lymphocytes. / Nishida, Motohiro; Sugimoto, Kenji; Hara, Yuji; Mori, Emiko; Morii, Takashi; Kurosaki, Tomohiro; Mori, Yasuo.
In: EMBO Journal, Vol. 22, No. 18, 15.09.2003, p. 4677-4688.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Amplification of receptor signalling by Ca2+ entry-mediated translocation and activation of PLCγ2 in B lymphocytes
AU - Nishida, Motohiro
AU - Sugimoto, Kenji
AU - Hara, Yuji
AU - Mori, Emiko
AU - Morii, Takashi
AU - Kurosaki, Tomohiro
AU - Mori, Yasuo
PY - 2003/9/15
Y1 - 2003/9/15
N2 - In non-excitable cells, receptor-activated Ca2+ signalling comprises initial transient responses followed by a Ca2+ entry-dependent sustained and/or oscillatory phase. Here, we describe the molecular mechanism underlying the second phase linked to signal amplification. An in vivo inositol 1,4,5-trisphosphate (IP3) sensor revealed that in B lymphocytes, receptor-activated and store-operated Ca2+ entry greatly enhanced IP3 production, which terminated in phospholipase Cγ2 (PLCγ2)-deficient cells. Association between receptor-activated TRPC3 Ca2+ channels and PLCγ2, which cooperate in potentiating Ca2+ responses, was demonstrated by co-immunoprecipitation. PLCγ2-deficient cells displayed diminished Ca2+ entry-induced Ca2+ responses. However, this defect was canceled by suppressing IP3-induced Ca2+ release, implying that IP3 and IP3 receptors mediate the second Ca2+ phase. Furthermore, confocal visualization of PLCγ2 mutants demonstrated that Ca2+ entry evoked a C2 domain-mediated PLCγ2 translocation towards the plasma membrane in a lipase-independent manner to activate PLCγ2. Strikingly, Ca2+ entry-activated PLCγ2 maintained Ca2+ oscillation and extracellular signal-regulated kinase activation downstream of protein kinase C. We suggest that coupling of Ca 2+ entry with PLCγ2 translocation and activation controls the amplification and co-ordination of receptor signalling.
AB - In non-excitable cells, receptor-activated Ca2+ signalling comprises initial transient responses followed by a Ca2+ entry-dependent sustained and/or oscillatory phase. Here, we describe the molecular mechanism underlying the second phase linked to signal amplification. An in vivo inositol 1,4,5-trisphosphate (IP3) sensor revealed that in B lymphocytes, receptor-activated and store-operated Ca2+ entry greatly enhanced IP3 production, which terminated in phospholipase Cγ2 (PLCγ2)-deficient cells. Association between receptor-activated TRPC3 Ca2+ channels and PLCγ2, which cooperate in potentiating Ca2+ responses, was demonstrated by co-immunoprecipitation. PLCγ2-deficient cells displayed diminished Ca2+ entry-induced Ca2+ responses. However, this defect was canceled by suppressing IP3-induced Ca2+ release, implying that IP3 and IP3 receptors mediate the second Ca2+ phase. Furthermore, confocal visualization of PLCγ2 mutants demonstrated that Ca2+ entry evoked a C2 domain-mediated PLCγ2 translocation towards the plasma membrane in a lipase-independent manner to activate PLCγ2. Strikingly, Ca2+ entry-activated PLCγ2 maintained Ca2+ oscillation and extracellular signal-regulated kinase activation downstream of protein kinase C. We suggest that coupling of Ca 2+ entry with PLCγ2 translocation and activation controls the amplification and co-ordination of receptor signalling.
UR - http://www.scopus.com/inward/record.url?scp=0141848670&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0141848670&partnerID=8YFLogxK
U2 - 10.1093/emboj/cdg457
DO - 10.1093/emboj/cdg457
M3 - Article
C2 - 12970180
AN - SCOPUS:0141848670
VL - 22
SP - 4677
EP - 4688
JO - EMBO Journal
JF - EMBO Journal
SN - 0261-4189
IS - 18
ER -