Identification of Functionally Distinct Isoforms of the N-Type Ca2+ Channel in Rat Sympathetic Ganglia and Brain

• Published in: Neuron (Cambridge, Mass.) Vol. 18; no. 1; pp. 153 - 166
• Main Authors: Lin, Zhixin, Haus, Stephanie, Edgerton, Jeremy, Lipscombe, Diane
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.1997
• Subjects: Alternative Splicing; Amino Acid Sequence; Animals; Base Sequence; Brain - metabolism; Calcium Channels - biosynthesis; Calcium Channels - chemistry; Calcium Channels - physiology; Chloride Channels - physiology; DNA Primers; Female; Gene Expression; Genetic Variation; Mammals; Membrane Potentials; Mice; Molecular Sequence Data; Oocytes - physiology; Organ Specificity; Polymerase Chain Reaction; Rabbits; Rats; Rats, Sprague-Dawley; Recombinant Proteins - biosynthesis; Sequence Homology, Amino Acid; Superior Cervical Ganglion - metabolism; Transcription, Genetic; Xenopus laevis
• ISSN: 0896-6273; 1097-4199
• DOI: 10.1016/S0896-6273(01)80054-4

The N channel is critical for regulating release of neurotransmitter at many synapses, and even subtle differences in its activity would be expected to influence the efficacy of synaptic transmission. Although several splice variants of the N channel are expressed in the mammalian nervous system, their biological importance is presently unclear. Here, we show that variants of the α1B subunit of the N channel are expressed in sympathetic ganglia and that alternative splicing within IIIS3-S4 and IVS3-S4 generate kinetically distinct channels. We further show a striking difference between the expression pattern of the S3-S4 variants in brain and peripheral ganglia and conclude that the brain-dominant form of the N channel gates 2- to 4-fold more rapidly than that predominant in ganglia.