Abstract
Inositol 1,4,5-trisphosphate (IP3) receptors are ligand-gated channels that release intracellular Ca2+ stores in response to the second messenger, IP3. We investigated the potential role of IP3 receptors during nuclear envelope assembly in vitro, using Xenopus egg extracts. Previous work suggested that Ca2+ mobilization is required for nuclear vesicle fusion and implicated IP3 receptor activity. To test the involvement of IP3 receptors using selective reagents, we obtained three distinct polyclonal antibodies to the type I IP3 receptor. Pretreatment of membranes with two of the antibodies inhibited IP3-stimulated Ca2+ release in vitro and also inhibited nuclear vesicle fusion. One inhibitory serum was directed against 420 residues within the 'coupling' domain, which includes several potential regulatory sites. The other inhibitory serum was directed against 95 residues near the C terminus and identifies an inhibitory epitope(s) in this region. The antibodies had no effect on receptor affinity for IP3. Because nuclear vesicle fusion was inhibited by antibodies that block Ca2+ flux, but not by control and preimmune antibodies, we concluded that the activation of IP3 receptors is required for fusion. The signal that activates the channel during fusion is unknown.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 8611-8615 |
| Number of pages | 5 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 92 |
| Issue number | 19 |
| DOIs | |
| State | Published - Sep 12 1995 |
Fingerprint
ASJC Scopus subject areas
- Genetics
- General
Cite this
Inhibition of nuclear vesicle fusion by antibodies that block activation of inositol 1,4,5-trisphosphate receptors. / Sullivan, Kathleen M C; Lin, Doris; Agnew, William; Wilson, Katherine Lee.
In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 92, No. 19, 12.09.1995, p. 8611-8615.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Inhibition of nuclear vesicle fusion by antibodies that block activation of inositol 1,4,5-trisphosphate receptors
AU - Sullivan, Kathleen M C
AU - Lin, Doris
AU - Agnew, William
AU - Wilson, Katherine Lee
PY - 1995/9/12
Y1 - 1995/9/12
N2 - Inositol 1,4,5-trisphosphate (IP3) receptors are ligand-gated channels that release intracellular Ca2+ stores in response to the second messenger, IP3. We investigated the potential role of IP3 receptors during nuclear envelope assembly in vitro, using Xenopus egg extracts. Previous work suggested that Ca2+ mobilization is required for nuclear vesicle fusion and implicated IP3 receptor activity. To test the involvement of IP3 receptors using selective reagents, we obtained three distinct polyclonal antibodies to the type I IP3 receptor. Pretreatment of membranes with two of the antibodies inhibited IP3-stimulated Ca2+ release in vitro and also inhibited nuclear vesicle fusion. One inhibitory serum was directed against 420 residues within the 'coupling' domain, which includes several potential regulatory sites. The other inhibitory serum was directed against 95 residues near the C terminus and identifies an inhibitory epitope(s) in this region. The antibodies had no effect on receptor affinity for IP3. Because nuclear vesicle fusion was inhibited by antibodies that block Ca2+ flux, but not by control and preimmune antibodies, we concluded that the activation of IP3 receptors is required for fusion. The signal that activates the channel during fusion is unknown.
AB - Inositol 1,4,5-trisphosphate (IP3) receptors are ligand-gated channels that release intracellular Ca2+ stores in response to the second messenger, IP3. We investigated the potential role of IP3 receptors during nuclear envelope assembly in vitro, using Xenopus egg extracts. Previous work suggested that Ca2+ mobilization is required for nuclear vesicle fusion and implicated IP3 receptor activity. To test the involvement of IP3 receptors using selective reagents, we obtained three distinct polyclonal antibodies to the type I IP3 receptor. Pretreatment of membranes with two of the antibodies inhibited IP3-stimulated Ca2+ release in vitro and also inhibited nuclear vesicle fusion. One inhibitory serum was directed against 420 residues within the 'coupling' domain, which includes several potential regulatory sites. The other inhibitory serum was directed against 95 residues near the C terminus and identifies an inhibitory epitope(s) in this region. The antibodies had no effect on receptor affinity for IP3. Because nuclear vesicle fusion was inhibited by antibodies that block Ca2+ flux, but not by control and preimmune antibodies, we concluded that the activation of IP3 receptors is required for fusion. The signal that activates the channel during fusion is unknown.
UR - http://www.scopus.com/inward/record.url?scp=0029027826&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0029027826&partnerID=8YFLogxK
U2 - 10.1073/pnas.92.19.8611
DO - 10.1073/pnas.92.19.8611
M3 - Article
C2 - 7567984
AN - SCOPUS:0029027826
VL - 92
SP - 8611
EP - 8615
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 19
ER -