Amino acid residues in both the DNA-binding and ligand-binding domains influence transcriptional activity of the human peroxisome proliferator-activated receptor alpha.
We have investigated the basis of the lack of activity of a natural variant human peroxisome proliferator-activated receptor alpha, hPPARalpha6/29. A subcloning approach was used to change the four variant amino acids in the hPPARalpha6/29 sequence, individually and in combination, to those found in an active human PPARalpha. Individual amino acid "back mutations" were unable to confer on hPPARalpha6/29 the ability to be activated by peroxisome proliferators in a transient transfection assay. Although hPPARalpha6/29 was able to bind specifically to DNA in the presence of the retinoid X receptor alpha (RXRalpha), the complete restoration of receptor transcriptional activity required two separate back mutations of the hPPARalpha6/29 sequence, namely amino acid 123 in the DNA binding domain, and amino acid 444 close to the C-terminus. This suggests that sequences in the PPARalpha DNA binding domain influence other receptor functions besides DNA binding.
Myers
K A
KA
Zeneca Central Toxicology Laboratory, Alderley Park, Macclesfield, Cheshire, United Kingdom.
Lambe
K G
KG
Aldridge
T C
TC
Macdonald
N
N
Tugwood
J D
JD
D000409:Alanine / Q000235:genetics / Q000502:physiology; D019943:Amino Acid Substitution / Q000235:genetics; D000596:Amino Acids / Q000235:genetics* / Q000502:physiology; D004247:DNA / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D008715:Methionine / Q000235:genetics / Q000502:physiology; D008830:Microbodies / Q000235:genetics*; D011485:Protein Binding / Q000235:genetics; D017434:Protein Structure, Tertiary; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic
D000596:Amino Acids; D008024:Ligands; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors; D004247:DNA; D008715:Methionine; D000409:Alanine