Mutant/mutation
The mutant expresses a C-terminal cmyc-tagged version of PlasMei2.

Protein (function)
Regulation of mRNA translation relies on RNA binding proteins (RBPs), many of which  form complexes within the cytoplasm in entities known as processing bodies (P-bodies) or P granules. P-bodies are involved in many aspects of mRNA homeostasis including both mRNA decay and translational repression.
Mei2 was initially described in the fission yeast Schizosaccharomyces pombe, and plays a critical role in the switch from mitosis to meiosis (20). Mei2 is a member of the largest family of RBPs – those that contain a RNA recognition motif (RRM), a stretch of 70-90 amino acids that contain two consensus RNA-interacting motifs, RNP1 and RNP2. RRM-containing proteins are subdivided into ten separate families (RRM_1 thru RRM_10) based on shared amino acid identities between members of each family and Mei2 contains a C-terminal RRM_2, thought to be unique to fungi and plants.
Plasmodium contains a single Mei2-like gene (from herein referred to as PlasMei2). In the P. yoelii rodent malaria model, Plasmei2 is only expressed during liver stage development and is localized in distinct cytoplasmic structures reminiscent of P-granules
Mei2-like genes are restricted to eukaryotic genomes and fall into three broad clades, the AML and TEL groups of plants, and a fungal clade. Interestingly, PlasMei2 cannot be exclusively assigned to any one group. Yeast Mei2 contains three RRMs, two N-terminal RRM_1 domains and a C-terminal RRM_2. Only the C-terminal RRM_2 domain is present in PlasMei2.
The Plasmodium RRM_2 shows a high degree of similarity to other Mei2 RRM_2 domains, based on a comparison to representative sequences from alveolates, fungi, and plants. The RRM_2 domain shares amino acid conservation with RRMs of the Sex Lethal and HuD proteins, both of which bind single-stranded AU-rich RNA, suggesting that PlasMei2 may behave similarly.

Phenotype

Analysis of a mutant lacking Plasmei2 (RMgm-1413) showed the following: Normal development/growth of asexual blood stages. Normal sporozoite production. Plasmei2‾ sporozoites failed to initiate a blood stage infection (after injection of 5x10(4) purified sporozoites). Abnormal development of liver stages. Growth arrest of late liver stages.

Analysis of the mutant expressing a myc-tagged version of Plasmei2 showed the following: transgenic parasites showed normal development throughout the complete life cycle inicating that the myc-tag did not affect the function of Plasmei2.

In addition, evidence is presented that PlasMei2 is only expressed in liver stages. At 20 hours of liver stage development, PlasMei2  expression was not observed, However, by 32 hours of development, PlasMei2 expression was observed throughout the liver stage cytoplasm and exhibited a granular localization pattern reminiscent of P-granule localization. Localization continued to be cytoplasmic and granular as the liver stage parasite matured at both 38 and 45 hours post infection before declining to undetectable levels at 52 hours.

Additional information

Other mutants
See RMgm-1413 for a mutant lacking expression of PlasMei2.