TY - JOUR
T1 - Alternative splicing in the pore-forming region of shaker potassium channels
AU - Kim, Marshall
AU - Baro, Deborah J.
AU - Lanning, Cathy C.
AU - Doshi, Mehul
AU - Farnham, Jeremy
AU - Moskowitz, Howard S.
AU - Peck, Jack H.
AU - Olivera, Baldomero M.
AU - Harris-Warrick, Ronald M.
PY - 1997
Y1 - 1997
N2 - We have cloned cDNAs for the shaker potassium channel gene from the spiny lobster Panulirus interruptus. As previously found in Drosophila, there is alternative splicing at the 5' and 3' ends of the coding region. However, in Panulirus shaker, alternative splicing also occurs within the pore- forming region of the protein. Three different splice variants were found within the P region, two of which bestow unique electrophysiological characteristics to channel function. Pore I and pore II variants differ in voltage dependence for activation, kinetics of inactivation, current rectification, and drug resistance. The pore 0 variant lacks a P region exon and does not produce a functional channel. This is the first example of alternative splicing within the pore-forming region of a voltage-dependent ion channel. We used a recently identified potassium channel blocker, κ- conotoxin PVIIA, to study the physiological role of the two pore forms. The toxin selectively blocked one pore form, whereas the other form, heteromers between the two pore forms, and Panulirus shal were not blocked. When it was tested in the Panulirus stomatogastric ganglion, the toxin produced no effects on transient K+ currents or synaptic transmission between neurons.
AB - We have cloned cDNAs for the shaker potassium channel gene from the spiny lobster Panulirus interruptus. As previously found in Drosophila, there is alternative splicing at the 5' and 3' ends of the coding region. However, in Panulirus shaker, alternative splicing also occurs within the pore- forming region of the protein. Three different splice variants were found within the P region, two of which bestow unique electrophysiological characteristics to channel function. Pore I and pore II variants differ in voltage dependence for activation, kinetics of inactivation, current rectification, and drug resistance. The pore 0 variant lacks a P region exon and does not produce a functional channel. This is the first example of alternative splicing within the pore-forming region of a voltage-dependent ion channel. We used a recently identified potassium channel blocker, κ- conotoxin PVIIA, to study the physiological role of the two pore forms. The toxin selectively blocked one pore form, whereas the other form, heteromers between the two pore forms, and Panulirus shal were not blocked. When it was tested in the Panulirus stomatogastric ganglion, the toxin produced no effects on transient K+ currents or synaptic transmission between neurons.
KW - Alternative splicing
KW - Conotoxin
KW - Pore-forming region
KW - Potassium channel
KW - Shaker
KW - Stomatogastric
UR - http://www.scopus.com/inward/record.url?scp=0030773751&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030773751&partnerID=8YFLogxK
U2 - 10.1523/jneurosci.17-21-08213.1997
DO - 10.1523/jneurosci.17-21-08213.1997
M3 - Article
C2 - 9334397
AN - SCOPUS:0030773751
SN - 0270-6474
VL - 17
SP - 8213
EP - 8224
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 21
ER -