TY - JOUR
T1 - Gap junction channel gating
AU - Bukauskas, Feliksas F.
AU - Verselis, Vytas K.
N1 - Funding Information:
We would like to thank all our collaborators and co-authors in the papers that were employed in this review and specifically to: Dr. T.A. Bargiello, Dr. M.V.L. Bennett, Dr. A. Bukauskiene, Dr. D. Laird, Dr. S. Oh, Dr. C. Peracchia, Dr. E.B. Trexler, Dr. R. Weingart, Dr. K. Willecke. This work was supported by NIH Grants: NS36706 to F.F.B. and GM54179 to V.K.V.
PY - 2004/3/23
Y1 - 2004/3/23
N2 - Over the last two decades, the view of gap junction (GJ) channel gating has changed from one with GJs having a single transjunctional voltage-sensitive (Vj-sensitive) gating mechanism to one with each hemichannel of a formed GJ channel, as well as unapposed hemichannels, containing two, molecularly distinct gating mechanisms. These mechanisms are termed fast gating and slow or 'loop' gating. It appears that the fast gating mechanism is solely sensitive to Vj and induces fast gating transitions between the open state and a particular substate, termed the residual conductance state. The slow gating mechanism is also sensitive to Vj, but there is evidence that this gate may mediate gating by transmembrane voltage (Vm), intracellular Ca2+ and pH, chemical uncouplers and GJ channel opening during de novo channel formation. A distinguishing feature of the slow gate is that the gating transitions appear to be slow, consisting of a series of transient substates en route to opening and closing. Published reports suggest that both sensorial and gating elements of the fast gating mechanism are formed by transmembrane and cytoplamic components of connexins among which the N terminus is most essential and which determines gating polarity. We propose that the gating element of the slow gating mechanism is located closer to the central region of the channel pore and serves as a 'common' gate linked to several sensing elements that are responsive to different factors and located in different regions of the channel.
AB - Over the last two decades, the view of gap junction (GJ) channel gating has changed from one with GJs having a single transjunctional voltage-sensitive (Vj-sensitive) gating mechanism to one with each hemichannel of a formed GJ channel, as well as unapposed hemichannels, containing two, molecularly distinct gating mechanisms. These mechanisms are termed fast gating and slow or 'loop' gating. It appears that the fast gating mechanism is solely sensitive to Vj and induces fast gating transitions between the open state and a particular substate, termed the residual conductance state. The slow gating mechanism is also sensitive to Vj, but there is evidence that this gate may mediate gating by transmembrane voltage (Vm), intracellular Ca2+ and pH, chemical uncouplers and GJ channel opening during de novo channel formation. A distinguishing feature of the slow gate is that the gating transitions appear to be slow, consisting of a series of transient substates en route to opening and closing. Published reports suggest that both sensorial and gating elements of the fast gating mechanism are formed by transmembrane and cytoplamic components of connexins among which the N terminus is most essential and which determines gating polarity. We propose that the gating element of the slow gating mechanism is located closer to the central region of the channel pore and serves as a 'common' gate linked to several sensing elements that are responsive to different factors and located in different regions of the channel.
KW - Channel
KW - Connexin
KW - Intercellular communication
KW - Voltage and chemical gating
UR - http://www.scopus.com/inward/record.url?scp=1642273067&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=1642273067&partnerID=8YFLogxK
U2 - 10.1016/j.bbamem.2004.01.008
DO - 10.1016/j.bbamem.2004.01.008
M3 - Review article
C2 - 15033578
AN - SCOPUS:1642273067
SN - 0005-2736
VL - 1662
SP - 42
EP - 60
JO - Biochimica et Biophysica Acta - Biomembranes
JF - Biochimica et Biophysica Acta - Biomembranes
IS - 1-2
ER -