2-pore Ca+2 Ca+2 protein 1 (voltage-dependent Ca+2 channel protein TPC1, TPCN1, KIAA1169, TPC1)

Function

• major voltage-gated Ca+2 channel across plasma membrane

Structure

• belongs to the Ca+2 channel alpha-1 subunit family
• dimer
• each of the 2 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 & are characterized by a series of positively charged amino acids at every third position

Compartment

membrane

Alternative splicing

named isoforms=2

Expression

• highest expression found in heart & kidney
• lowest expression found in the spleen

More general terms

• transmembrane 12 protein
• voltage-dependent Ca+2 channel-alpha

Database

• UniProt: http://www.uniprot.org/uniprot/Q9ULQ1.html