Amino Acid Mutation Scheme | TM No. | Expression System | Characterization | Reference |
---|---|---|---|---|
Human | ||||
G24E | NTerm | COS-7 | Heterozygous polymorphism with no phenotype. When expressed in COS-7 cells no change in Kd or Ki with melatonin. | Ebisawa et al., 2000 |
L66F | 1.58 | COS-7 | Heterozygous polymorphism with no phenotype. | Ebisawa et al., 2000 |
C113A | ECL1 | HEK293 | No specific binding. | Mseeh et al., 2002 |
C140A | ICL2 | HEK293 | No change in Kd, slightly increased Ki for melatonin (1.6×), decreased Bmax (22×). | Mseeh et al., 2002 |
C143A | ICL2 | HEK293 | No change in Kd, slightly increased Ki for melatonin (1.4×), slightly increased Bmax (1.8×). | Mseeh et al., 2002 |
C190A | ECL2 | HEK293 | No specific binding. | Mseeh et al., 2002 |
C219A | 5.57 | HEK293 | No change in Kd or Ki. Decreased Bmax (5×). | Mseeh et al., 2002 |
C263A | 6.47 | HEK293 | No change in Kd or Ki. Decreased Bmax (31×). | Mseeh et al., 2002 |
C302A | 7.47 | HEK293 | No change in Kd or Ki. Decreased Bmax (4×). | Mseeh et al., 2002 |
S123A | 3.35 | HEK293 | No change in Kd or Ki. Decreased Bmax (5×). | Gerdin et al., 2003 |
S127A | 3.39 | HEK293 | No change in Kd or Ki. Decreased Bmax (3×). | Gerdin et al., 2003 |
N175Aa | 4.60 | HEK293 | No change in Kd, slightly increased Ki for melatonin. No change in Bmax. | Gerdin et al., 2003 |
H208Aa | 5.46 | HEK293 | Increased Kd and Ki for melatonin. No change in Bmax. | Gerdin et al., 2003 |
F257A | 6.41 | HEK293 | No change in Kd or Ki. No change in Bmax. | Gerdin et al., 2003 |
W264A | 6.48 | HEK293 | Decreased Kd, no change in Ki. Decreased Bmax (22×). | Gerdin et al., 2003 |
S293A | 7.38 | HEK293 | No change in Kd or Ki. No change in Bmax. | Gerdin et al., 2003 |
V204Aa | 5.42 | HEK293 | No specific binding. | Mazna et al., 2004 |
V205 | 5.43 | HEK293 | No change in Kd. No change in Bmax. | Mazna et al., 2004 |
F209A | 5.47 | HEK293 | No change in Kd. Decreased Bmax. No change in Ki for melatonin, luzindole or 4P-PDOT. | Mazna et al., 2004 |
G271T | 6.55 | HEK293 | Not saturable. | Mazna et al., 2004 |
L272Aa | 6.56 | HEK293 | No specific binding. | Mazna et al., 2004 |
Y298Aa | 7.43 | HEK293 | No specific binding. | Mazna et al., 2004 |
M120A | 3.32 | HEK293 | No change in Kd or Bmax. | Mazna et al., 2005 |
G121A | 3.33 | HEK293 | No change in Kd or Bmax. | Mazna et al., 2005 |
G121I | 3.33 | HEK293 | No change in Kd or Bmax. | Mazna et al., 2005 |
V124A | 3.36 | HEK293 | No change in Kd with decreased Bmax. | Mazna et al., 2005 |
I125A | 3.37 | HEK293 | No change in Kd or Bmax. | Mazna et al., 2005 |
Y188A | ECL2 | HEK293 | No specific binding. | Mazna et al., 2005 |
Y188F | ECL2 | HEK293 | No specific binding. | Mazna et al., 2005 |
N268Aa | 6.52 | HEK293 | No specific binding. | Mazna et al., 2005 |
N268Da | 6.52 | HEK293 | No specific binding. | Mazna et al., 2005 |
N268La | 6.52 | HEK293 | No specific binding. | Mazna et al., 2005 |
N268Qa | 6.52 | HEK293 | No change in Kd or Bmax. | Mazna et al., 2005 |
A275I | 6.59 | HEK293 | No specific binding. | Mazna et al., 2005 |
A275Va | 6.59 | HEK293 | No change in Kd or Bmax. | Mazna et al., 2005 |
V291Aa | 7.36 | HEK293 | No specific binding. | Mazna et al., 2005 |
V291Ia | 7.36 | HEK293 | No specific binding. | Mazna et al., 2005 |
L295Aa | 7.40 | HEK293 | No specific binding. | Mazna et al., 2005 |
L295Ia | 7.40 | HEK293 | No specific binding. | Mazna et al., 2005 |
L295Va | 7.40 | HEK293 | No specific binding. | Mazna et al., 2005 |
Hamster | ||||
P41A | 1.33 | CHO-K1 | No change in Kd or Bmax. No change in EC50 or Emax for melatonin or 2-iodomelatonin stimulation of GTPγ35S binding. | Mazna et al., 2008 |
P93A | 2.57 | CHO-K1 | No change in Kd or Bmax. No change in EC50 or Emax for melatonin or 2-iodomelatonin stimulation of GTPγ35S binding. | Mazna et al., 2008 |
P95A | 2.59 | CHO-K1 | No change in Kd or Bmax. No change in EC50 or Emax for melatonin or 2-iodomelatonin stimulation of GTPγ35S binding. | Mazna et al., 2008 |
P158A | 4.40 | CHO-K1 | No change in Kd or Bmax. No change in EC50 or Emax for melatonin or 2-iodomelatonin stimulation of GTPγ35S binding. | Mazna et al., 2008 |
P174A | 4.59 | CHO-K1 | No specific binding. | Mazna et al., 2008 |
P174G | 4.59 | CHO-K1 | No specific binding. | Mazna et al., 2008 |
P212A | 5.50 | CHO-K1 | No change in Kd or Bmax. Decreased Emax for melatonin and 2-iodomelatonin, stimulation of GTPγ35S binding. | Mazna et al., 2008 |
P212G | 5.50 | CHO-K1 | No change in Kd or Bmax. Increased EC50 for 2-iodomelatonin stimulation of GTPγ35S binding with no change in Emax. | Mazna et al., 2008 |
P266A | 6.50 | CHO-K1 | No specific binding. | Mazna et al., 2008 |
P266G | 6.50 | CHO-K1 | No specific binding. | Mazna et al., 2008 |
A305P | 7.50 | CHO-K1 | No specific binding. | Mazna et al., 2008 |
A305V | 7.50 | CHO-K1 | No change for Kd or Bmax. Increased EC50 for melatonin and 2-iodomelatonin stimulation of GTPγ35S binding with decreased Emax. | Mazna et al., 2008 |
HEK, human embryonic kidney; CHO, Chinese hamster ovary.
↵a Amino acid residues important for modulating binding to the MT1 receptor (Farce et al., 2008).