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- *******************************************************
- * Sodium:neurotransmitter symporter family signatures *
- *******************************************************
-
- After their release by synapses the action of a number of neurotransmitters
- is terminated by their high affinity sodium-dependent reuptake into
- presynaptic terminals by specific transport proteins [1 to 4]. These proteins
- are the target of psychomotor stimulants such as amphetamines or cocaine. All
- these proteins belong to a family, known [5] as the sodium:neurotransmitter
- symporter family (SNF), that also include some transporters that function
- outside the brain and carry related molecules. The SNF family is currently
- known to consist of transporters for:
-
- - Betaine (also transports GABA).
- - Choline.
- - Creatine.
- - Dopamine.
- - GABA (four different forms of GABA transporters have been characterized).
- - Glycine.
- - Noradrenaline.
- - Proline.
- - Serotonin (5HT).
- - Taurine.
-
- - Rat orphan transporter NTT4.
- - Caenorhabditis elegans hypothetical transporter T23G5.5.
-
- All these transporters are glycoproteins of about 600 to 700 amino acid
- residues which seem to contain 12 transmembrane domains. Apparently both
- termini are cytoplasmically located.
-
- As signature patterns for these proteins we have selected two highly conserved
- regions. The first region spans the C-terminal part of the first transmembrane
- domain, a short extracellular loop, and the N-terminal part of the second
- transmembrane domain. The second region is located in the largest
- extracellular loop between the third and fourth transmembrane domains; this
- region contains two conserved cysteines that could be involved in disulfide
- bonds.
-
- -Consensus pattern: W-R-F-P-Y-x-[CA]-x(2)-N-G-G-G-x-[FY]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Consensus pattern: Y-[LIVMFY]-x(2)-[SC]-[LIVMFY]-[STQ]-x(2)-L-P-W-x(2)-C-
- x(4)-N-[GST]
- [The C could be involved in a disulfide bond]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Last update: June 1994 / Patterns and text revised.
-
- [ 1] Snyder S.H.
- Nature 354:187-187(1991).
- [ 2] Schloss P., Mayser W., Betz H.
- FEBS Lett. 307:76-80(1992).
- [ 3] Attwell D., Bouvier M.
- Curr. Biol. 2:541-543(1992).
- [ 4] Uhl G.R.
- Trends Neurosci. 15:265-268(1992).
- [ 5] Reizer J., Reizer A., Saier M.H. Jr.
- Submitted(1993).
-