Additional remarks phenotype | Mutant/mutation
The mutant expresses a C-terminal GFP-tagged version of AP2-G2
Protein (function)
Apetala 2 (AP2)-family proteins are transcription factors that have DNA-binding domains of 60 amino acids called AP2 domains. Recently, AP2 genes have been found in the genomes of Plasmodium parasites. In P. falciparum 27 AP2-family genes have been identified. Among these genes, 26 are conserved in the other Plasmodium species whose entire genomes have been sequenced. Each member of this family has 1 to 4 AP2 domains, and the amino acid sequences of these domains are highly conserved among Plasmodium orthologs.
Phenotype
Based on analyses of mutants lacking AP2-G2 (RMgm-1340, RMgm-1341) evidence is presented that the lack of AP2-G2 expression did not abrogate sexual commitment or sex determination but did cause marked developmental defects in the gametocytes, together with a marked reduction of sex-specific gene expression. Evidence is presented that AP2-G2 is a transcriptional repressor in sexually committed trophozoites.
In analyses using mutant P. berghei parasites expressing GFP-tagged AP2-G2 (AP2-G2::GFP parasites), it was found that AP2-G2 was specifically expressed in female and male gametocytes. The GFP signal was solely observed in the nucleus, suggesting that AP2-G2 acts as a transcription factor in gametocytes. In a temporal profiling analysis of AP2-G2 expression using synchronized blood cultures, expression was first observed from 16 h after erythrocyte invasion (hpi) until development into mature male or female gametocytes. The timing of expression correlated well with the onset of morphological divergence from the asexual stage (16–18 hpi), strongly suggesting that this transcription factor is involved in gametocyte-specific gene expression.
Additional information
Other mutants
See link for other AP2-G2 mutants. |