Direct interaction of two homeoproteins, homothorax and extradenticle, is essential for EXD nuclear localization and function.
The Drosophila Homothorax (HTH) and Extradenticle (EXD) are two homeoproteins required in a number of developmental processes. EXD can function as a cofactor to Hox proteins. Its nuclear localization is dependent on HTH. In this study we present evidence of in vivo physical interaction between HTH and EXD, mediated primarily through an evolutionarily conserved MH domain in HTH. This interaction is essential for the mutual stabilization of both proteins, for EXD nuclear localization, and for the cooperative DNA binding of the EXD-HTH heterodimer. Some in vivo functions require both EXD and HTH in the nucleus, suggesting that the EXD-HTH complex may function as a transcriptional regulator.
Jaw
T J
TJ
Institute of Genetics, National Yang-Ming University, Shipai, Taipei, Taiwan.
You
L R
LR
Knoepfler
P S
PS
Yao
L C
LC
Pai
C Y
CY
Tang
C Y
CY
Chang
L P
LP
Berthelsen
J
J
Blasi
F
F
Kamps
M P
MP
Sun
Y H
YH
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002467:Cell Nucleus / Q000378:metabolism; D017124:Conserved Sequence; D004247:DNA / Q000378:metabolism; D004330:Drosophila / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D029721:Drosophila Proteins; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism* / Q000502:physiology
D029721:Drosophila Proteins; D018398:Homeodomain Proteins; C106682:PKNOX1 protein, human; C491412:Pknox1 protein, mouse; D014157:Transcription Factors; C083405:exd protein, Drosophila; C108704:hth protein, Drosophila; D004247:DNA