A putative two pore channel AtTPC1 mediates Ca2+ flux in Arabidopsis leaf cells

Citation
T. Furuichi et al., A putative two pore channel AtTPC1 mediates Ca2+ flux in Arabidopsis leaf cells, PLANT CEL P, 42(9), 2001, pp. 900-905
Citations number
34
Categorie Soggetti
Plant Sciences","Animal & Plant Sciences
Journal title
PLANT AND CELL PHYSIOLOGY
ISSN journal
00320781 → ACNP
Volume
42
Issue
9
Year of publication
2001
Pages
900 - 905
Database
ISI
SICI code
0032-0781(200109)42:9<900:APTPCA>2.0.ZU;2-P
Abstract
The gene encoding voltage-gated channel with high affinity for Ca2+ permeat ion has not been cloned from plants. In the present study, we isolated a fu ll-length cDNA encoding a putative Ca2+ channel (AtTPC1) from Arabidopsis. AtTPC1 has two conserved homologous domains, both of which contain six tran smembrane segments (S1-S6) and a pore loop (P) between S5 and S6 in each do main, and has the highest homology with the two pore channel TPC1 recently cloned from rat. The overall structure is similar to the half of the genera l structure of alpha -subunits of voltage-activated Ca2+ channels from anim als. AtTPC1 rescued the Ca2+ uptake activity of a yeast mutant cch1. Sucros e-induced luminescence, which reflects a cytosolic free Ca2+ increase in ae quorin-expressing Arabidopsis leaves, was enhanced by overexpression of AtT PC1 and suppressed by antisense expression of it. Sucrose-H+ symporters AtS UC1 and 2, which depolarize membrane potential of cells receiving sucrose, also depressed a Ca2+ increase by their antisense expression. These results suggest that AtTPC1 mediates a voltage-activated Ca2+ influx in Arabidopsi s leaf cells.