PMID- 11677251
OWN - NLM
STAT- MEDLINE
DCOM- 20011204
LR  - 20221207
IS  - 0022-3042 (Print)
IS  - 0022-3042 (Linking)
VI  - 79
IP  - 2
DP  - 2001 Oct
TI  - Species-scanning mutagenesis of the serotonin transporter reveals residues 
      essential in selective, high-affinity recognition of antidepressants.
PG  - 237-47
AB  - The serotonin transporter (SERT) is a high-affinity sodium/chloride-dependent 
      neurotransmitter transporter responsible for reuptake of serotonin from the 
      extracellular space. SERT is a selective target of several clinically important 
      antidepressants. In a cross-species analysis comparing human and bovine SERTs, 
      the kinetic parameters for serotonin uptake were found to be similar, however, 
      the pharmacological profiles of the two transporters differ. Following transient 
      expression in COS-1 cells, IC(50) values were determined for several 
      antidepressants and psychostimulants. The potencies of the antidepressants 
      citalopram, fluoxetine, paroxetine and imipramine were several-fold higher at 
      hSERT compared with bSERT. No species selectivity was observed for the 
      antidepressants fluvoxamine, and sertraline or for the psychostimulants cocaine, 
      the cocaine analogue beta-carbomethoxy-3beta-(4-iodophenyl)tropane, or for 
      3,4-methylenedioxymethamphetamine (MDMA). Analysis of six hSERT/bSERT chimeras 
      and subsequent species-scanning mutagenesis of each isoform revealed 
      methionine-180, tyrosine-495, and phenylalanine-513 to be responsible for the 
      increase in citalopram and paroxetine potencies at hSERT and methionine-180 and 
      phenylalanine-513 to confer species selectivity at hSERT for fluoxetine and 
      imipramine. Results were obtained by doing the forward, bovine to human, 
      mutations and confirmed by doing the reverse mutations. Citalopram analogues were 
      used to define the roles of methionine-180, tyrosine-495, and phenylalanine-513 
      and to reveal molecular interactions with individual functional groups of 
      citalopram. We suggest that methionine-180 interacts with the heterocyclic 
      nucleus of citalopram or stabilizes the binding pocket and phenylalanine-513 to 
      be a steric blocker of antidepressant recognition.
FAU - Mortensen, O V
AU  - Mortensen OV
AD  - Laboratory of Molecular Neurobiology, Department of Biological Psychiatry, 
      Psychiatric University Hospital, Risskov, Denmark.
FAU - Kristensen, A S
AU  - Kristensen AS
FAU - Wiborg, O
AU  - Wiborg O
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - J Neurochem
JT  - Journal of neurochemistry
JID - 2985190R
RN  - 0 (Antidepressive Agents)
RN  - 0 (Antidepressive Agents, Second-Generation)
RN  - 0 (Carrier Proteins)
RN  - 0 (Membrane Glycoproteins)
RN  - 0 (Membrane Transport Proteins)
RN  - 0 (Nerve Tissue Proteins)
RN  - 0 (SLC6A4 protein, human)
RN  - 0 (Serotonin Plasma Membrane Transport Proteins)
RN  - 0 (Serotonin Uptake Inhibitors)
RN  - 0DHU5B8D6V (Citalopram)
RN  - 333DO1RDJY (Serotonin)
SB  - IM
MH  - Animals
MH  - Antidepressive Agents/*pharmacology
MH  - Antidepressive Agents, Second-Generation/pharmacology
MH  - COS Cells
MH  - Carrier Proteins/*drug effects/*genetics/metabolism
MH  - Cattle
MH  - Chimera
MH  - Citalopram/analogs & derivatives
MH  - Humans
MH  - Membrane Glycoproteins/*drug effects/*genetics/metabolism
MH  - *Membrane Transport Proteins
MH  - Mutagenesis, Site-Directed
MH  - *Nerve Tissue Proteins
MH  - Serotonin/metabolism
MH  - Serotonin Plasma Membrane Transport Proteins
MH  - Selective Serotonin Reuptake Inhibitors/pharmacology
MH  - Species Specificity
EDAT- 2001/10/26 10:00
MHDA- 2002/01/05 10:01
CRDT- 2001/10/26 10:00
PHST- 2001/10/26 10:00 [pubmed]
PHST- 2002/01/05 10:01 [medline]
PHST- 2001/10/26 10:00 [entrez]
AID - 10.1046/j.1471-4159.2001.00587.x [doi]
PST - ppublish
SO  - J Neurochem. 2001 Oct;79(2):237-47. doi: 10.1046/j.1471-4159.2001.00587.x.