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Cloning and functional expression of human short TRP7, a candidate protein for store-operated Ca2+ influx.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 2002 Apr 05; Vol. 277 (14), pp. 12302-9. Date of Electronic Publication: 2002 Jan 22. - Publication Year :
- 2002
-
Abstract
- The regulation and control of plasma membrane Ca(2+) fluxes is critical for the initiation and maintenance of a variety of signal transduction cascades. Recently, the study of transient receptor potential channels (TRPs) has suggested that these proteins have an important role to play in mediating capacitative calcium entry. In this study, we have isolated a cDNA from human brain that encodes a novel transient receptor potential channel termed human TRP7 (hTRP7). hTRP7 is a member of the short TRP channel family and is 98% homologous to mouse TRP7 (mTRP7). At the mRNA level hTRP7 was widely expressed in tissues of the central nervous system, as well as some peripheral tissues such as pituitary gland and kidney. However, in contrast to mTRP7, which is highly expressed in heart and lung, hTRP7 was undetectable in these tissues. For functional analysis, we heterologously expressed hTRP7 cDNA in an human embryonic kidney cell line. In comparison with untransfected cells depletion of intracellular calcium stores in hTRP7-expressing cells, using either carbachol or thapsigargin, produced a marked increase in the subsequent level of Ca(2+) influx. This increased Ca(2+) entry was blocked by inhibitors of capacitative calcium entry such as La(3+) and Gd(3+). Furthermore, transient transfection of an hTRP7 antisense expression construct into cells expressing hTRP7 eliminated the augmented store-operated Ca(2+) entry. Our findings suggest that hTRP7 is a store-operated calcium channel, a finding in stark contrast to the mouse orthologue, mTRP7, which is reported to enhance Ca(2+) influx independently of store depletion, and suggests that human and mouse TRP7 channels may fulfil different physiological roles.
- Subjects :
- Amino Acid Sequence
Brain metabolism
Calcium Channel Blockers pharmacology
Cell Line
Central Nervous System embryology
Cloning, Molecular
DNA, Complementary metabolism
Enzyme Inhibitors pharmacology
Epitopes
Exons
Female
Gene Library
Humans
Imidazoles pharmacology
Ion Channels metabolism
Kidney metabolism
Male
Manganese metabolism
Molecular Sequence Data
Oligonucleotides, Antisense pharmacology
Phylogeny
Pituitary Gland metabolism
Protein Binding
RNA, Messenger metabolism
Reverse Transcriptase Polymerase Chain Reaction
Sequence Homology, Amino Acid
TRPM Cation Channels
Thapsigargin pharmacology
Time Factors
Tissue Distribution
Transfection
Calcium metabolism
Ion Channels chemistry
Membrane Proteins
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9258
- Volume :
- 277
- Issue :
- 14
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 11805119
- Full Text :
- https://doi.org/10.1074/jbc.M112313200