标题：Familial hemiplegic migraine mutations increase Ca2+ influx through single human CaV2.1 channels and decrease maximal CaV2.1 current density in neurons
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2002
卷号：99
期号：20
页码：13284-13289
DOI：10.1073/pnas.192242399
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Insights into the pathogenesis of migraine with aura may be gained from a study of human CaV2.1 channels containing mutations linked to familial hemiplegic migraine (FHM). Here, we extend the previous single-channel analysis to human CaV2.1 channels containing mutation V1457L. This mutation increased the channel open probability by shifting its activation to more negative voltages and reduced both the unitary conductance and the density of functional channels in the membrane. To investigate the possibility of changes in CaV2.1 function common to all FHM mutations, we calculated the product of single-channel current and open probability as a measure of Ca2+ influx through single CaV2.1 channels. All five FHM mutants analyzed showed a single-channel Ca2+ influx larger than wild type in a broad voltage range around the threshold of activation. We also expressed the FHM mutants in cerebellar granule cells from CaV2.11-/- mice rather than HEK293 cells. The FHM mutations invariably led to a decrease of the maximal CaV2.1 current density in neurons. Current densities were similar to wild type at lower voltages because of the negatively shifted activation of FHM mutants. Our data show that mutational changes of functional channel densities can be different in different cell types, and they uncover two functional effects common to all FHM mutations analyzed: increase of single-channel Ca2+ influx and decrease of maximal CaV2.1 current density in neurons. We discuss the relevance of these findings for the pathogenesis of migraine with aura.
