PfADA2, a Plasmodium falciparum homologue of the transcriptional coactivator ADA2 and its in vivo association with the histone acetyltransferase PfGCN5.
The transcriptional coactivator ADA2 is an evolutionarily conserved component of histone acetyltransferase (HAT) complexes involved in chromatin remodeling and transcriptional regulation in eukaryotes. The Plasmodium falciparum homologue, PfADA2, has a 7737 bp open reading frame, encoding a protein of 2578 amino acids with an ADA2-like domain located near the C-terminus. The annotated PfADA2 in the parasite genome is Pf10_143, located on chromosome 10. Sequence analysis demonstrated the presence of an ADA2 homologue in each Plasmodium species selected for genome sequencing. Mapping of the 5' transcriptional initiation sites suggested that PfADA2 transcription was initiated from multiple sites. Northern analysis detected a major transcript of approximately 8.5 kb in erythrocytic stage parasites. An antiserum raised against the internal ADA2-like domain detected multiple proteins from mixed blood stages, suggesting that PfADA2 may be proteolytically processed. In comparison, affinity-purified anti-GCN5 antibodies reacted with a major protein of approximately 200 kDa and immunoprecipitated proteins from the parasite lysate with HAT activity similar to that of the recombinant GCN5. Moreover, this GCN5-like HAT activity could also be precipitated with anti-PfADA2 antibodies, indicating that PfADA2 is associated with PfGCN5 in vivo. To illustrate whether PfADA2 could functionally replace the yADA2, complementation experiments were performed. However, the ADA2-like domain of PfADA2 failed to rescue the yeast ada2(-) mutant, probably due to significant divergence between the two genes. Taken together, these results indicate the presence of PfADA2-PfGCN5 complex(es) in the malaria parasite, which may have conserved functions in chromatin remodeling and gene regulation.
Fan
Qi
Q
Department of BioScience and Technology, Dalian University of Technology, Dalian 116012, China.
An
Lijia
L
Cui
Liwang
L
D000123:Acetyltransferases / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D005816:Genetic Complementation Test; D051548:Histone Acetyltransferases; D008969:Molecular Sequence Data; D009154:Mutation; D010963:Plasmodium falciparum / Q000235:genetics* / Q000378:metabolism; D011485:Protein Binding; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
C492089:ADA2 protein, Plasmodium falciparum; C090575:ADA2 protein, S cerevisiae; D016054:DNA, Protozoan; D015800:Protozoan Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D000123:Acetyltransferases; D051548:Histone Acetyltransferases