The beta subunit of voltage-dependent calcium channels contributes to the function of the calcium channel by increasing peak calcium current, shifting the voltage dependencies of activation and inactivation, modulating G protein inhibition and controlling the alpha-1 subunit membrane targeting.
Catalysis of the transmembrane transfer of a calcium ion by a high voltage-gated channel. A high voltage-gated channel is a channel whose open state is dependent on high voltage across the membrane in which it is embedded.
Catalysis of the transmembrane transfer of a calcium ion by a voltage-gated channel. A voltage-gated channel is a channel whose open state is dependent on the voltage across the membrane in which it is embedded.
J. Biol. Chem. 267, 22967-22972 (1992)[PubMed:1385409]
Clones of the beta 1-subunit of the voltage-dependent calcium channel (VDCC) from human skeletal muscle and hippocampus cDNA libraries, and from human genomic libraries, were isolated using a human skeletal muscle beta 1 cDNA probe generated by polymerase chain reaction. The skeletal muscle beta 1 cDNA (beta 1M) encodes a protein of 523 amino acids that is 97% identical to the rabbit skeletal muscle beta-subunit. Two different cDNAs, beta 1B1 and beta 1B2, were obtained from the human hippocampus library. The beta 1B1 transcript encodes a protein of 478 amino acids that is identical to the skeletal muscle beta-subunit (beta 1M), except for an internal region of 52 amino acids. The beta 1B2 transcript encodes a protein of 596 amino acids. The beta 1B2 polypeptide is identical to the beta 1B1 polypeptide at amino acids 1-444; however, it has a unique 152 amino acid carboxyl terminus. Like beta 1B1, it differs from beta 1M at the internal 52 amino acids. Analysis of the beta 1 gene structure demonstrates that these three cDNAs represent transcripts encoded by a single beta 1 gene. Transcripts from the beta 1 gene were detected in RNA from skeletal muscle, heart, spleen, and brain, but not in RNA from liver, stomach, or kidney.
The directed movement of substances (such as macromolecules, small molecules, ions) into, out of or within a cell, or between cells, or within a multicellular organism by means of some agent such as a transporter or pore.
J. Biol. Chem. 267, 22967-22972 (1992)[PubMed:1385409]
Clones of the beta 1-subunit of the voltage-dependent calcium channel (VDCC) from human skeletal muscle and hippocampus cDNA libraries, and from human genomic libraries, were isolated using a human skeletal muscle beta 1 cDNA probe generated by polymerase chain reaction. The skeletal muscle beta 1 cDNA (beta 1M) encodes a protein of 523 amino acids that is 97% identical to the rabbit skeletal muscle beta-subunit. Two different cDNAs, beta 1B1 and beta 1B2, were obtained from the human hippocampus library. The beta 1B1 transcript encodes a protein of 478 amino acids that is identical to the skeletal muscle beta-subunit (beta 1M), except for an internal region of 52 amino acids. The beta 1B2 transcript encodes a protein of 596 amino acids. The beta 1B2 polypeptide is identical to the beta 1B1 polypeptide at amino acids 1-444; however, it has a unique 152 amino acid carboxyl terminus. Like beta 1B1, it differs from beta 1M at the internal 52 amino acids. Analysis of the beta 1 gene structure demonstrates that these three cDNAs represent transcripts encoded by a single beta 1 gene. Transcripts from the beta 1 gene were detected in RNA from skeletal muscle, heart, spleen, and brain, but not in RNA from liver, stomach, or kidney.
Protein involved in the transport of calcium ions. Calcium is essential for a variety of bodily functions, such as neurotransmission, muscle contraction and proper heart function.
Protein involved in the transport of ions. Such proteins are usually transmembrane and mediate a movement of ions across cell membranes. Transport may be passive (facilitated diffusion; down the electrochemical gradient), or active (against the electrochemical gradient). Active transport requires energy which may come from light, oxidation reactions, ATP hydrolysis, or cotransport of other ions or molecules.
Protein involved in the transport of a molecule (metabolite, protein, etc), a ion or an electron across cell membranes, inside the cell or in a tissue fluid.
Cell membrane glycoprotein forming a channel in a biological membrane selectively permeable to calcium ions. Calcium is essential for a variety of bodily functions, such as neurotransmission, muscle contraction and proper heart function.
Protein which is part of a transmembrane protein complex that forms a hydrophilic channel across the lipid bilayer through which specific inorganic ions can diffuse down their electrochemical gradients. The channels are usually gated and only open in response to a specific stimulus, such as a change in membrane potential (voltage-gated) or the binding of a ligand (ligand-gated channel).
Protein which is a component of a voltage-gated channel. Voltage-gated ion channels are responsible for the electrical activity in a variety of cell types. They probably exist in all life forms.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.