Linked Life Data

15664175

Source:http://linkedlifedata.com/resource/pubmed/id/15664175

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2005-1-24
pubmed:abstractText
Voltage-gated sodium channels with "resurgent" kinetics are specialized for high-frequency firing. The alpha subunits interact with a blocking protein that binds open channels upon depolarization and unbinds upon repolarization, producing resurgent sodium current. By limiting classical inactivation, the cycle of block and unblock shortens refractory periods. To characterize the blocker in Purkinje neurons, we briefly exposed inside-out patches to substrate-specific proteases. Trypsin and chymotrypsin each removed resurgent current, consistent with established roles for positively charged and hydrophobic/aromatic groups in blocking sodium channels. In Purkinje cells, the only known sodium channel-associated subunit that has a cytoplasmic sequence with several positive charges and clustered hydrophobic/aromatic residues is beta4 (KKLITFILKKTREK; beta4(154-167)). After enzymatic removal of block, beta4(154-167) fully reconstituted resurgent current, whereas scrambled or point-mutated peptides were ineffective. In CA3 pyramidal neurons, which lack beta4 and endogenous block, beta4(154-167) generated resurgent current. Thus, beta4 may be the endogenous open-channel blocker responsible for resurgent kinetics.
pubmed:grant
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0896-6273
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
45
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
233-44
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Open-channel block by the cytoplasmic tail of sodium channel beta4 as a mechanism for resurgent sodium current.
pubmed:affiliation
Institute for Neuroscience, Northwestern University, Evanston, IL 60208, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't