Additional remarks phenotype | Mutant/mutation
The mutant expresses GFP under the control of the 5'-UTR of SERA3 (the ortholog of P. falciparum SERA6)
Protein (function)
Plasmodium species possesses SERAs of two major groups, specified as 'cysteine-type SERAs' and 'serine-type SERAs'. Serine-type SERAs contain an active site serine residue instead of the canonical cysteine residue. The genomes of different Plasmodium species contain different numbers of SERA genes. P. falciparum possesses nine SERA protease genes whereas the P. berghei genome contains five. P. falciparum possesses six “serine-type” (SERA1 to SERA5 and SERA9) and three “cysteine-type” (SERA6 to SERA8) SERAs. In P. falciparum mutants have been generated lacking expression of SERA1, 2, 3, 4 , 7, 8 and 9 without a distinct phenotype in the blood stages (MvCoubrie J.E. et al, 2007, Infection and Immunity, 75:5565-74).
SERA genes of P. berghei are arranged in a tandem cluster that contains two serine-type SERAs (PbSERA1, -2) and three cysteine-type SERAs (PbSERA3, -4 and -5).
Sequence homology and syntenic organisation indicate that PbSERA3, -4 (PB000352.01.0) and -5 (PB000649.01.0) are orthologs of P. falciparum SERA6, -7, -8.
Phenotype
The phenotype analyses of the liverstages indicate that the promoter of PbSERA3 is active towards the end of the exoerythrocytic stage, in particular during merozoite formation, confirming RT-PCR analyses of transcription (see 'Additional Information').
Additional information
In the paper RT-PCR data is presented on transcription of the five SERA genes of P. berghei. PbSERA1-4 are expressed both in blood and liver stages. PbSERA5 is expressed in oocysts and sporozoites.
Other mutants
RMgm-102: A mutant lacking expression of SERA8 (PB000649.01.0; PFB0325c), a cysteine-type SERA homologue (serine repeat antigen 8, SERA-8; ECP1, egress cysteine protease 1; PbSERA5)
RMgm-272: The mutant expresses in addition to the endogenous SERA3 (the ortholog of P. falciparum SERA6) a TAP-tagged form of SERA3 under control of its own 5'-UTR and the dhfr/ts 3'-UTR
RMgm-365: A mutant expressing the endogenous SERA1 protein fused to the mCherry red fluorescent protein
RMgm-366: A mutant expressing the endogenous SERA2 protein fused to the mCherry red fluorescent protein
RMgm-367: A knock-out mutant lacking expression of SERA1
RMgm-368: A knock-out mutant lacking expression of SERA2
RMgm-369: A double knock-out mutant lacking expression of SERA1 and SERA2 |