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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
2005-5-3
pubmed:abstractText
Mutation S218L in the Ca(V)2.1 alpha(1) subunit of P/Q-type Ca(2+) channels produces a severe clinical phenotype in which typical attacks of familial hemiplegic migraine (FHM) triggered by minor head trauma are followed, after a lucid interval, by deep (even fatal) coma and long lasting severe cerebral edema. We investigated the functional consequences of this mutation on human Ca(V)2.1 channels expressed in human embryonic kidney 293 cells and in neurons from Ca(V)2.1 alpha(1)(-/-) mice by combining single channel and whole cell patch clamp recordings. Mutation S218L produced a shift to lower voltages of the single channel activation curve and a consequent increase of both single channel and whole cell Ba(2+) influx in both neurons and human embryonic kidney 293 cells. Compared with the other FHM-1 mutants, the S218L shows one of the largest gains of function, especially for small depolarizations, which are insufficient to open the wild-type channel. S218L channels open at voltages close to the resting potential of many neurons. Moreover, the S218L mutation has unique effects on the kinetics of inactivation of the channel because it introduces a large component of current that inactivates very slowly, and it increases the rate of recovery from inactivation. During long depolarizations at voltages that are attained during cortical spreading depression, the extent of inactivation of the S218L channel is considerably smaller than that of the wild-type channel. We discuss how the unique combination of a particularly slow inactivation during cortical spreading depression and a particularly low threshold of channel activation might lead to delayed severe cerebral edema and coma after minor head trauma.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
17678-86
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Specific kinetic alterations of human CaV2.1 calcium channels produced by mutation S218L causing familial hemiplegic migraine and delayed cerebral edema and coma after minor head trauma.
pubmed:affiliation
Department of Biomedical Sciences, University of Padova, CNR Institute of Neuroscience, Viale G. Colombo 3, 35121 Padova, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't