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A calcium channel in human submandibular duct cell line, HSG cells, not regulated by P2U purinergic receptor-mediated intracellular calcium mobilization.
- Source :
-
Archives of oral biology [Arch Oral Biol] 1997 Aug; Vol. 42 (8), pp. 547-57. - Publication Year :
- 1997
-
Abstract
- Signal transduction via P2 purinergic receptors was investigated in HSG cells, a continuous cell line originally derived from an irradiated human salivary gland. Ligand specificity for nucleotide receptors in HSG cells was investigated with various nucleotides and their analogues. Inositol 1,4,5-trisphosphate (IP3) production was significantly increased by ATP, UTP and ATP gamma S. The ligand specificity of this effect agreed well with that of the P2U purinergic receptor. On the other hand, 45Ca2+ influx was stimulated by ATP, UTP > ATP gamma S, ADP, UDP > ADP beta S > AMPPNP, GTP, TTP > CTP, GDP, TDP, AMPPCP, AMPCPP. This ligand specificity of 45Ca2+ influx was much broader than IP3 production. Also pertussis and cholera toxin had no effect on both IP3 production and 45Ca2+ influx by ATP or UTP. 3'-O-(4-benzoylbenzoyl)adenosine 5'-triphosphate (Bz-ATP) stimulates 45Ca2+ influx more effectively than IP3 formation. A 53-kDa membrane protein was photolabelled with [alpha-32P]Bz-ATP. This 53-kDa protein is a putative P2 purinergic receptor. In particular, the labelling was inhibited by a ligand profile that corresponded to that for 45Ca2+ influx. These findings suggest that nucleotides stimulate 45Ca2+ influx and IP3 formation by separate pathways via pertussis and cholera toxin-insensitive G proteins. Thus, in HSG cells, IP3 formation is coupled to the P2U subclass, while 45Ca2+ influx is coupled to another subclass, such as P2X, that regulates calcium channels.
- Subjects :
- Adenine Nucleotides pharmacology
Adenosine Diphosphate analogs & derivatives
Adenosine Diphosphate metabolism
Adenosine Diphosphate pharmacology
Adenosine Triphosphate analogs & derivatives
Adenosine Triphosphate pharmacology
Adenylyl Imidodiphosphate pharmacology
Affinity Labels
Calcium Radioisotopes
Cell Line
Cholera Toxin pharmacology
Cytidine Triphosphate pharmacology
GTP-Binding Proteins drug effects
Guanosine Diphosphate pharmacology
Humans
Inositol 1,4,5-Trisphosphate biosynthesis
Ligands
Membrane Proteins drug effects
Pertussis Toxin
Radiopharmaceuticals
Salivary Ducts cytology
Submandibular Gland cytology
Substrate Specificity
Thionucleotides pharmacology
Thymine Nucleotides pharmacology
Uridine Triphosphate pharmacology
Virulence Factors, Bordetella pharmacology
Calcium metabolism
Calcium Channels drug effects
Receptors, Purinergic drug effects
Salivary Ducts drug effects
Signal Transduction drug effects
Submandibular Gland drug effects
Subjects
Details
- Language :
- English
- ISSN :
- 0003-9969
- Volume :
- 42
- Issue :
- 8
- Database :
- MEDLINE
- Journal :
- Archives of oral biology
- Publication Type :
- Academic Journal
- Accession number :
- 9347117
- Full Text :
- https://doi.org/10.1016/s0003-9969(97)89060-7