Voltage Dependent Ca+2 Channel Alpha 1i

Function

pore-forming & voltage-sensitive alpha-1 subunit of voltage-sensitive Ca+2 channel
alpha-1I gives rise to T-type Ca+2 currents

T-type Ca+2 channels belong to the low-voltage activated (LVA) group
strongly blocked by nickel & mibefradil
a particularity of T-type Ca+2 channels is an opening at negative potentials, & a voltage-dependent inactivation
T-type channels serve pacemaking functions in both central neurons & cardiac nodal cells
role in Ca+2 signaling in secretory cells & vascular smooth muscle
role in modulation of firing patterns of neurons during information processing
role in cell growth processes
T-type Ca+2 channels are activated by CaM-kinase III in response to increasing intracellular Ca+2

gates in voltage ranges similar to, but higher than alpha-1G or alpha-1H ( putative)
interacts with CATSPER1 & CATSPER2, leading to suppress T-type Ca+2 channel activity

each of the 4 internal repeats contains 5 hydrophobic transmembrane segments (S1, S2, S3, S5, S6) & one positively charged transmembrane segment (S4).
S4 segments probably represent the voltage- sensor; they are characterized by a series of positively charged amino acids at every third position
belongs to the Ca+2 channel alpha-1 subunit (TC 1.A.1.11) family

Entrez gene: 8911
Kegg: [1]
OMIM: 608230
UniProt: [2]

UniProt [3]