Functional role of position 22 in the homeodomain of Brn-3 transcription factors.
The Brn-3a POU family transcription factor activates a number of neuronal promoters which are repressed by the closely related Brn-3b factor. Although transcriptional activation by mutant forms of Brn-3a/Brn-3b can occur with a number of different amino acids at position 22 of the POU homeodomain, an isoleucine at this position is of critical importance for transcriptional repression. In addition, this isoleucine residue can mediate an interaction with the herpes simplex virus Vmw65 regulatory protein whereas the valine found in Brn-3a cannot do so. Thus, position 22 in the homeodomain plays a critical role in the function of neuronally expressed POU factors by controlling their interaction with viral and cellular co-activator/co-repressor proteins.
Department of Molecular Pathology, The Windeyer Institute of Medical Sciences, University College London Medical School, UK.
S J
SJ
Dawson
R D
RD
Palmer
P J
PJ
Morris
D S
DS
Latchman
D000818:Animals; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D006224:Cricetinae; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D005347:Fibroblasts; D017405:Herpes Simplex Virus Protein Vmw65 / Q000235:genetics / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D006801:Humans; D007532:Isoleucine / Q000235:genetics; D016297:Mutagenesis, Site-Directed; D009474:Neurons / Q000378:metabolism; D010957:Plasmids; D050818:Transcription Factor Brn-3; D050819:Transcription Factor Brn-3A; D050820:Transcription Factor Brn-3B; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic; D014162:Transfection / Q000235:genetics; D014633:Valine / Q000235:genetics
D004268:DNA-Binding Proteins; D017405:Herpes Simplex Virus Protein Vmw65; D018398:Homeodomain Proteins; C494188:POU4F1 protein, human; C494190:POU4F2 protein, human; D050818:Transcription Factor Brn-3; D050819:Transcription Factor Brn-3A; D050820:Transcription Factor Brn-3B; D014157:Transcription Factors; D007532:Isoleucine; D015500:Chloramphenicol O-Acetyltransferase; D014633:Valine