Details
| Original language | English |
|---|---|
| Pages (from-to) | 627-9 |
| Number of pages | 3 |
| Journal | Pflugers Archiv European Journal of Physiology |
| Volume | 436 |
| Issue number | 4 |
| Publication status | Published - Jul 1998 |
Abstract
Hemichannels of rat connexin 46 (rCx46) were expressed in Xenopus laevis oocytes and analysed by two-electrode voltage-clamp experiments. It is established that rCx46 hemichannels can be activated at low external Ca2+ and positive membrane potentials. Upon larger depolarizations, the hemichannels of oocytes activate in a time-dependent manner, occasionally followed by a spontaneous inactivation. We found that, in the absence of inactivation, treatment of oocytes with 1-oleoyl-2-acetyl-sn-glycerol (OAG), an activator of protein kinase C (PKC), reversibly reduced the amplitude of the rCx46-mediated current and, after an incubation time of about 30 min, induced inactivation of the voltage-dependent current. After wash-out of OAG the corresponding membrane conductance increased and the inactivation behaviour disappeared. The OAG-induced inactivation, as well as the spontaneous inactivation, could be removed by application of the specific PKC inhibitor calphostin C and also by phloretin. The data provide evidence that the activation and inhibition of PKC affect the rCx46-mediated membrane conductance as well as the voltage-dependent current inactivation in an inverse manner.
Keywords
- Animals, Connexins/antagonists & inhibitors, Diglycerides/metabolism, Oocytes/cytology, Patch-Clamp Techniques, Phosphorylation, Protein Kinase C/antagonists & inhibitors, Rats, Xenopus laevis
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In: Pflugers Archiv European Journal of Physiology, Vol. 436, No. 4, 07.1998, p. 627-9.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Inactivation of expressed and conducting rCx46 hemichannels by phosphorylation
AU - Ngezahayo, Anaclet
AU - Zeilinger, Carsten
AU - Todt, I.
AU - Marten, I.
AU - Kolb, Hans-Albert
PY - 1998/7
Y1 - 1998/7
N2 - Hemichannels of rat connexin 46 (rCx46) were expressed in Xenopus laevis oocytes and analysed by two-electrode voltage-clamp experiments. It is established that rCx46 hemichannels can be activated at low external Ca2+ and positive membrane potentials. Upon larger depolarizations, the hemichannels of oocytes activate in a time-dependent manner, occasionally followed by a spontaneous inactivation. We found that, in the absence of inactivation, treatment of oocytes with 1-oleoyl-2-acetyl-sn-glycerol (OAG), an activator of protein kinase C (PKC), reversibly reduced the amplitude of the rCx46-mediated current and, after an incubation time of about 30 min, induced inactivation of the voltage-dependent current. After wash-out of OAG the corresponding membrane conductance increased and the inactivation behaviour disappeared. The OAG-induced inactivation, as well as the spontaneous inactivation, could be removed by application of the specific PKC inhibitor calphostin C and also by phloretin. The data provide evidence that the activation and inhibition of PKC affect the rCx46-mediated membrane conductance as well as the voltage-dependent current inactivation in an inverse manner.
AB - Hemichannels of rat connexin 46 (rCx46) were expressed in Xenopus laevis oocytes and analysed by two-electrode voltage-clamp experiments. It is established that rCx46 hemichannels can be activated at low external Ca2+ and positive membrane potentials. Upon larger depolarizations, the hemichannels of oocytes activate in a time-dependent manner, occasionally followed by a spontaneous inactivation. We found that, in the absence of inactivation, treatment of oocytes with 1-oleoyl-2-acetyl-sn-glycerol (OAG), an activator of protein kinase C (PKC), reversibly reduced the amplitude of the rCx46-mediated current and, after an incubation time of about 30 min, induced inactivation of the voltage-dependent current. After wash-out of OAG the corresponding membrane conductance increased and the inactivation behaviour disappeared. The OAG-induced inactivation, as well as the spontaneous inactivation, could be removed by application of the specific PKC inhibitor calphostin C and also by phloretin. The data provide evidence that the activation and inhibition of PKC affect the rCx46-mediated membrane conductance as well as the voltage-dependent current inactivation in an inverse manner.
KW - Animals
KW - Connexins/antagonists & inhibitors
KW - Diglycerides/metabolism
KW - Oocytes/cytology
KW - Patch-Clamp Techniques
KW - Phosphorylation
KW - Protein Kinase C/antagonists & inhibitors
KW - Rats
KW - Xenopus laevis
U2 - 10.1007/s004240050681
DO - 10.1007/s004240050681
M3 - Article
C2 - 9683738
VL - 436
SP - 627
EP - 629
JO - Pflugers Archiv European Journal of Physiology
JF - Pflugers Archiv European Journal of Physiology
SN - 0031-6768
IS - 4
ER -