Functional architecture of atrophins.
Vertebrate genomes harbor two Atrophin genes, Atrophin-1 (Atn1) and Atrophin-2 (Atn2). The Atn1 locus produces a single polypeptide, whereas two different protein products are expressed from the Atn2 (also known as Rere) locus. A long, or full-length, form contains an amino-terminal MTA-2-homologous domain followed by an Atrophin-1-related domain. A short form, expressed via an internal promoter, consists solely of the Atrophin domain. Atrophin-1 can be co-immunoprecipitated along with Atrophin-2, suggesting that the Atrophins ordinarily function together. Mutations that disrupt the expression of the long form of Atrophin-2 disrupt early embryonic development. To determine the requirement for Atrophin-1 during development we generated a null allele. Somewhat surprisingly we found that Atrophin-1 function is dispensable. To gain a better understanding of the requirement for Atrophin function during development, an analysis of the functional domains of the three different gene products was carried out. Taken together, these data suggest that Atrophins function as bifunctional transcriptional regulators. The long form of Atrophin-2 has a transcriptional repression activity that is not found in the other Atrophin polypeptides and that is required for normal embryogenesis. Atrophin-1 and the short form of Atrophin-2, on the other hand, can act as potent and evolutionarily conserved transcriptional activators.
Shen
Yiguo
Y
Gallo Center and the Department of Neurology, University of California at San Francisco, Emeryville, California 94608.
Lee
Gena
G
Gallo Center and the Department of Neurology, University of California at San Francisco, Emeryville, California 94608.
Choe
Youngshik
Y
Gallo Center and the Department of Neurology, University of California at San Francisco, Emeryville, California 94608.
Zoltewicz
J Susie
JS
Gallo Center and the Department of Neurology, University of California at San Francisco, Emeryville, California 94608.
Peterson
Andrew S
AS
Gallo Center and the Department of Neurology, University of California at San Francisco, Emeryville, California 94608. Electronic address: Peterson.Andrew@gene.com.
D000818:Animals; D047108:Embryonic Development / Q000235:genetics / Q000502:physiology*; D019143:Evolution, Molecular; D015870:Gene Expression / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary / Q000235:genetics; D040641:Quantitative Trait Loci / Q000502:physiology*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation / Q000502:physiology*
D009419:Nerve Tissue Proteins; D012097:Repressor Proteins; C481983:atrophin 2, mouse; C095278:atrophin-1