Identification of putative voltage-dependent Ca2+-permeable channels involved in cryptogein-induced Ca2+ transients and defense responses in tobacco BY-2 cells.
Biochem Biophys Res Commun, 2004/5/07;317(3):823-30.
Kadota Y[1], Furuichi T, Ogasawara Y, Goh T, Higashi K, Muto S, Kuchitsu K
Affiliations
PMID: 15081414
Impact factor: 3.322
Abstract
Ca(2+) is the pivotal second messenger for induction of defense responses induced by treatment of pathogen-derived elicitor or microbial infection in plants. However, molecular bases for elicitor-induced generation of Ca(2+) signals (Ca(2+) transients) are largely unknown. We here identified cDNAs for putative voltage-dependent Ca(2+)-permeable channels, NtTPC1A and NtTPC1B, that are homologous to TPC1 (two pore channel) from suspension-cultured tobacco BY-2 cells. NtTPC1s complemented the growth of a Saccharomyces cerevisiae mutant defective in CCH1, a putative Ca(2+) channel, in a low Ca(2+) medium, suggesting that both products permeate Ca(2+) through the plasma membrane. Cosuppression of NtTPC1s in apoaequorin-expressing BY-2 cells resulted in inhibition of rise in cytosolic free Ca(2+) concentration ([Ca(2+)](cyt)) in response to sucrose and a fungal elicitor cryptogein, while it did not affect hypoosmotic shock-induced [Ca(2+)](cyt) increase. Cosuppression of NtTPC1s also caused suppression of cryptogein-induced programmed cell death and defense-related gene expression. These results suggest that NtTPC1s are involved in Ca(2+) mobilization induced by the cryptogein and sucrose, and have crucial roles in cryptogein-induced signal transduction pathway.
MeSH terms
Algal Proteins; Amino Acid Sequence; Base Sequence; Calcium; Calcium Channels; Cell Line; Cloning, Molecular; DNA Primers; Fungal Proteins; Molecular Sequence Data; Saccharomyces cerevisiae; Sequence Homology, Amino Acid; Nicotiana
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