Reviewed,
UniProtKB/Swiss-Prot O95180 (CAC1H_HUMAN)
Last modified
November 25, 2008.
Version 81.
History...
Clusters with 100%,
90%,
50% identity |
Documents (5) |
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Names and origin
| Protein names | Recommended name: Voltage-dependent T-type calcium channel subunit alpha-1H Alternative name(s): Voltage-gated calcium channel subunit alpha Cav3.2 Low-voltage-activated calcium channel alpha1 3.2 subunit | ||
| Gene names |
| ||
| Organism | Homo sapiens (Human) | ||
| Taxonomic identifier | 9606 [NCBI] | ||
| Taxonomic lineage | Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Primates › Haplorrhini › Catarrhini › Hominidae › Homo |
Protein attributes
| Sequence length | 2353 AA. |
| Sequence status | Complete. |
| Sequence processing | The displayed sequence is not processed. |
| Protein existence | Evidence at protein level. |
General annotation (Comments)
| Function | Voltage-sensitive calcium channels (VSCC) mediate the entry of calcium ions into excitable cells and are also involved in a variety of calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release, gene expression, cell motility, cell division and cell death. The isoform alpha-1H gives rise to T-type calcium currents. T-type calcium channels belong to the "low-voltage activated (LVA)" group and are strongly blocked by nickel and mibefradil. A particularity of this type of channels is an opening at quite negative potentials, and a voltage-dependent inactivation. T-type channels serve pacemaking functions in both central neurons and cardiac nodal cells and support calcium signaling in secretory cells and vascular smooth muscle. They may also be involved in the modulation of firing patterns of neurons which is important for information processing as well as in cell growth processes. |
| Subcellular location | |
| Tissue specificity | Expressed in kidney, liver, heart, brain. Isoform 2 seems to be testis-specific. |
| Domain | Each of the four internal repeats contains five hydrophobic transmembrane segments (S1, S2, S3, S5, S6) and one positively charged transmembrane segment (S4). S4 segments probably represent the voltage-sensor and are characterized by a series of positively charged amino acids at every third position. |
| Post-translational modification | In response to raising of intracellular calcium, the T-type channels are activated by CaM-kinase II. |
| Involvement in disease | Defects in CACNA1H are a cause of susceptibility to idiopathic generalized epilepsy type 6 (IGE6) [MIM:611942]. IGE is characterized by recurring generalized seizures in the absence of detectable brain lesions and/or metabolic abnormalities. Generalized seizures arise diffusely and simultaneously from both hemispheres of the brain. IGE6 is a polygenic and multifactorial disease. |
| Sequence similarities | Belongs to the calcium channel alpha-1 subunit (TC 1.A.1.11) family. [View classification] |
| Sequence caution | The sequence AAK61268.1 differs from that shown. Reason: Erroneous gene model prediction. The sequence CAC42094.1 differs from that shown. Reason: Erroneous gene model prediction. |
Ontologies
Keywords | |
|---|---|
| Biological process | Calcium transport Ion transport Transport |
| Cellular component | Membrane |
| Coding sequence diversity | Alternative splicing Polymorphism |
| Disease | Disease mutation Epilepsy |
| Domain | Repeat Transmembrane |
| Ligand | Calcium |
| Molecular function | Calcium channel Ionic channel Voltage-gated channel |
| PTM | Glycoprotein Phosphoprotein |
Gene Ontology (GO) | |
| Biological process | calcium ion transport Inferred from electronic annotation. Source: InterPro muscle contraction Ref.1Traceable author statement. Source: ProtInc myoblast fusionTraceable author statement. Source: ProtInc regulation of heart contraction Ref.1Traceable author statement. Source: ProtInc |
| Cellular component | voltage-gated calcium channel complex Traceable author statement. Source: ProtInc |
| Molecular function | calcium ion binding Inferred from electronic annotation. Source: UniProtKB-KW low voltage-gated calcium channel activityTraceable author statement. Source: ProtInc |
| Complete GO annotation... | |
Alternative products
| This entry describes 2 isoforms produced by alternative splicing. [Align] [Select] | ||||||
| Isoform 1 (identifier: O95180-1) Also known as: A1H-a; This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry. | ||||||
| Isoform 2 (identifier: O95180-2) Also known as: A1H-b; The sequence of this isoform differs from the canonical sequence as follows: 1587-1592: Missing. |
Sequence annotation (Features)
| Feature key | Position(s) | Length | Description | Graphical view | Feature identifier | ||||
Molecule processing | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Chain | 1 – 2353 | 2353 | Voltage-dependent T-type calcium channel subunit alpha-1H | PRO_0000053954 | |||||
Regions | |||||||||
| Topological domain | 1 – 100 | 100 | Cytoplasmic Potential | ||||||
| Transmembrane | 101 – 119 | 19 | S1 of repeat I Potential | ||||||
| Topological domain | 120 – 139 | 20 | Extracellular Potential | ||||||
| Transmembrane | 140 – 160 | 21 | S2 of repeat I Potential | ||||||
| Topological domain | 161 – 169 | 9 | Cytoplasmic Potential | ||||||
| Transmembrane | 170 – 184 | 15 | S3 of repeat I Potential | ||||||
| Topological domain | 185 – 193 | 9 | Extracellular Potential | ||||||
| Transmembrane | 194 – 212 | 19 | S4 of repeat I Potential | ||||||
| Topological domain | 213 – 232 | 20 | Cytoplasmic Potential | ||||||
| Transmembrane | 233 – 253 | 21 | S5 of repeat I Potential | ||||||
| Topological domain | 254 – 394 | 141 | Extracellular Potential | ||||||
| Transmembrane | 395 – 419 | 25 | S6 of repeat I Potential | ||||||
| Topological domain | 420 – 793 | 374 | Cytoplasmic Potential | ||||||
| Transmembrane | 794 – 814 | 21 | S1 of repeat II Potential | ||||||
| Topological domain | 815 – 827 | 13 | Extracellular Potential | ||||||
| Transmembrane | 828 – 849 | 22 | S2 of repeat II Potential | ||||||
| Topological domain | 850 – 855 | 6 | Cytoplasmic Potential | ||||||
| Transmembrane | 856 – 874 | 19 | S3 of repeat II Potential | ||||||
| Topological domain | 875 – 882 | 8 | Extracellular Potential | ||||||
| Transmembrane | 883 – 906 | 24 | S4 of repeat II Potential | ||||||
| Topological domain | 907 – 917 | 11 | Cytoplasmic Potential | ||||||
| Transmembrane | 918 – 938 | 21 | S5 of repeat II Potential | ||||||
| Topological domain | 939 – 990 | 52 | Extracellular Potential | ||||||
| Transmembrane | 991 – 1015 | 25 | S6 of repeat II Potential | ||||||
| Topological domain | 1016 – 1290 | 275 | Cytoplasmic Potential | ||||||
| Transmembrane | 1291 – 1313 | 23 | S1 of repeat III Potential | ||||||
| Topological domain | 1314 – 1331 | 18 | Extracellular Potential | ||||||
| Transmembrane | 1332 – 1352 | 21 | S2 of repeat III Potential | ||||||
| Topological domain | 1353 – 1362 | 10 | Cytoplasmic Potential | ||||||
| Transmembrane | 1363 – 1382 | 20 | S3 of repeat III Potential | ||||||
| Topological domain | 1383 – 1396 | 14 | Extracellular Potential | ||||||
| Transmembrane | 1397 – 1418 | 22 | S4 of repeat III Potential | ||||||
| Topological domain | 1419 – 1428 | 10 | Cytoplasmic Potential | ||||||
| Transmembrane | 1429 – 1452 | 24 | S5 of repeat III Potential | ||||||
| Topological domain | 1453 – 1529 | 77 | Extracellular Potential | ||||||
| Transmembrane | 1530 – 1555 | 26 | S6 of repeat III Potential | ||||||
| Topological domain | 1556 – 1616 | 61 | Cytoplasmic Potential | ||||||
| Transmembrane | 1617 – 1637 | 21 | S1 of repeat IV Potential | ||||||
| Topological domain | 1638 – 1651 | 14 | Extracellular Potential | ||||||
| Transmembrane | 1652 – 1673 | 22 | S2 of repeat IV Potential | ||||||
| Topological domain | 1674 – 1680 | 7 | Cytoplasmic Potential | ||||||
| Transmembrane | 1681 – 1699 | 19 | S3 of repeat IV Potential | ||||||
| Topological domain | 1700 – 1713 | 14 | Extracellular Potential | ||||||
| Transmembrane | 1714 – 1737 | 24 | S4 of repeat IV Potential | ||||||
| Topological domain | 1738 – 1751 | 14 | Cytoplasmic Potential | ||||||
| Transmembrane | 1752 – 1772 | 21 | S5 of repeat IV Potential | ||||||
| Topological domain | 1773 – 1835 | 63 | Extracellular Potential | ||||||
| Transmembrane | 1836 – 1863 | 28 | S6 of repeat IV Potential | ||||||
| Topological domain | 1864 – 2353 | 490 | Cytoplasmic Potential | ||||||
| Repeat | 87 – 422 | 336 | I | ||||||
| Repeat | 779 – 1018 | 240 | II | ||||||
| Repeat | 1281 – 1558 | 278 | III | ||||||
| Repeat | 1602 – 1863 | 262 | IV | ||||||
| Compositional bias | 520 – 530 | 11 | Poly-His | ||||||
| Compositional bias | 1107 – 1110 | 4 | Poly-Ser | ||||||
| Compositional bias | 1583 – 1586 | 4 | Poly-Arg | ||||||
Sites | |||||||||
| Site | 378 | 1 | Calcium ion selectivity and permeability By similarity | ||||||
| Site | 974 | 1 | Calcium ion selectivity and permeability By similarity | ||||||
| Site | 1504 | 1 | Calcium ion selectivity and permeability By similarity | ||||||
| Site | 1808 | 1 | Calcium ion selectivity and permeability By similarity | ||||||
Amino acid modifications | |||||||||
| Modified residue | 783 | 1 | Phosphoserine | ||||||
| Modified residue | 1191 | 1 | Phosphothreonine | ||||||
| Glycosylation | 192 | 1 | N-linked (GlcNAc...) Potential | ||||||
| Glycosylation | 271 | 1 | N-linked (GlcNAc...) Potential | ||||||
| Glycosylation | 1466 | 1 | N-linked (GlcNAc...) Potential | ||||||
Natural variations | |||||||||
| Alternative sequence | 1587 – 1592 | 6 | Missing in isoform 2. | VSP_000949 | |||||
| Natural variant | 161 | 1 | F → L in IGE6. | VAR_045935 | |||||
| Natural variant | 282 | 1 | E → K in IGE6. | VAR_045936 | |||||
| Natural variant | 313 | 1 | M → V: dbSNP rs36117280. | VAR_045937 | |||||
| Natural variant | 456 | 1 | C → S in IGE6. | VAR_045938 | |||||
| Natural variant | 499 | 1 | G → S in IGE6. | VAR_045939 | |||||
| Natural variant | 640 | 1 | P → L | VAR_045940 | |||||
| Natural variant | 648 | 1 | P → L in IGE6. | VAR_045941 | |||||
| Natural variant | 664 | 1 | V → A: dbSNP rs4984636. | VAR_045942 | |||||
| Natural variant | 684 | 1 | P → S | VAR_045943 | |||||
| Natural variant | 744 | 1 | R → Q in IGE6. | VAR_045944 | |||||
| Natural variant | 748 | 1 | A → V in IGE6. | VAR_045945 | |||||
| Natural variant | 773 | 1 | G → D in IGE6. | VAR_045946 | |||||
| Natural variant | 784 | 1 | G → S in IGE6. | VAR_045947 | |||||
| Natural variant | 788 | 1 | R → C: dbSNP rs3751664. | VAR_045948 | |||||
| Natural variant | 812 | 1 | V → M: dbSNP rs28365119. | VAR_045949 | |||||
| Natural variant | 831 | 1 | V → M in IGE6. | VAR_045950 | |||||
| Natural variant | 848 | 1 | G → S in IGE6. | VAR_045951 | |||||
| Natural variant | 1463 | 1 | D → N in IGE6. | ||||||

Clusters with