Pfmrk, A MO15‐Related Protein Kinase from Plasmodium falciparum

Open Access
Publisher Website
Google Scholar
Abstract
Cyclin‐dependent kinases (Cdks) play a central role in the regulation of the eukaryotic cell cycle. A novel gene encoding a Cdk‐like protein, Pfmrk, has been isolated from the human malaria parasite Plasmodium falciparum. The gene has no introns and comprises an open reading frame encoding a protein of 324 amino acids with a predicted molecular mass of 38 kDa. Database searches revealed a striking similarity to the Cdk subfamily with the highest similarity to human MO15 (Cdk7). The overall sequence of Pfmrk shares 62% similarity and 46% identity with human MO15, in comparison to the 49–58% similarity and 34–43% identity with other human Cdks. Pfmrk contains two unique inserts: one consisting of 5 amino acids just before the cyclin‐binding motif and the other composed of 13 amino acids within the T‐loop equivalent region. Southern blots of genomic DNA digests and chromosomal separations showed that Pfmrk is a single‐copy gene conserved between several parasite strains and is located on chromosome 10. A 2500‐nucleotide transcript of this gene is expressed predominantly in the sexual blood stages (gametocytes), suggesting that Pfmrk may be involved in sexual stage development.