RMgmDB - Rodent Malaria genetically modified Parasites

Summary

RMgm-407
Malaria parasiteP. berghei
Genotype
Transgene
Transgene not Plasmodium: PH domain of human phospholipase Cδ1 (hPLCδ1) fused to YFP and CFP
Promoter: Gene model: PBANKA_1133300; Gene model (P.falciparum): PF3D7_1357100; Gene product: elongation factor 1-alpha (eef1a)
3'UTR: Gene model: PBANKA_0719300; Gene product: bifunctional dihydrofolate reductase-thymidylate synthase, putative (dhfr/ts)
Phenotype Gametocyte/Gamete;
Last modified: 25 May 2011, 17:34
  *RMgm-407
Successful modificationThe parasite was generated by the genetic modification
The mutant contains the following genetic modification(s) Introduction of a transgene
Reference (PubMed-PMID number) Reference 1 (PMID number) : 21518218
MR4 number
Parent parasite used to introduce the genetic modification
Rodent Malaria ParasiteP. berghei
Parent strain/lineP. berghei ANKA
Name parent line/clone P. berghei ANKA 2.34
Other information parent lineP. berghei ANKA 2.34 is a cloned, gametocyte producer line of the ANKA strain (PubMed: PMID: 15137943)
The mutant parasite was generated by
Name PI/ResearcherA.C. Raabe; O. Billker; H.J. Vial
Name Group/DepartmentUMR5235
Name InstituteCNRS-Université Montpellier
CityMontpellier
CountryFrance
Name of the mutant parasite
RMgm numberRMgm-407
Principal nameCFP–PH–YFP
Alternative name
Standardized name
Is the mutant parasite cloned after genetic modificationYes
Phenotype
Asexual blood stageNot tested
Gametocyte/GameteIn most gametocytes of either sex the CFP–PH–YFP protein was clearly detectable in the periphery of the cells, consistent with a localization at the plasma membrane (see for more details 'additional remarks phenotype')
Fertilization and ookineteNot tested
OocystNot tested
SporozoiteNot tested
Liver stageNot tested
Additional remarks phenotype

Mutant/mutation
The mutant expresses a fusion protein consisting of the PH domain of human phospholipase Cδ1 (hPLCδ1) fused to yellow fluorescent protein (YFP) and cyan fluorescent protein (CFP). The gene encoding this fusion protein is expressed under the control of the constitutive eef1α promoter and introduced into the parasites as episomal plasmids.

Protein (function)
The study analyses Ca2+ mobilization in (activated) gametocytes by phosphoinositide specific phospholipase C (PI-PLC; PBANKA_121190,  PF10_0132), which hydrolyses the minor membrane lipid phosphatidylinositol-(4,5)-bisphosphate (PIP2), producing the secondary messengers inositol-(1,4,5)-trisphosphate (IP3) and diacylglycerol (DAG); IP3 then triggers Ca2+ release into the cytosol by binding to IP3-gated Ca2+ channels localized predominately in the ER membrane.
In the paper evidence is presented that activation of gametocytes (to produce gametes) is triggered by the hydrolysis of PIP2 and the production of the secondary messenger IP3 in activated gametocytes. Both processes were selectively blocked by a PI-PLC inhibitor, which also reduced the early Ca2+ signal.

Dynamic changes in cellular PIP2 have been monitored successfully in cultured mammalian cells by single cell imaging of a fluorescent reporter protein fused to the PH domain of human phospholipase Cδ1 (hPLCδ1). PH domains can bind both, PIP2 and IP3. Resting cells contain low IP3 levels and a PH domain-containing reporter protein is targeted mostly to the plasma membrane where PIP2 resides. PI-PLC activation and IP3 production then leads to translocation of the probe to the cytoplasm

Phenotype
In most resting gametocytes of either sex the CFP–PH–YFP protein was clearly detectable in the periphery of the cells, consistent with a localization at the plasma membrane. By time lapse microscopy it was observed that within two minutes of activation of gametocytes, the CFP–PH–YFP protein began to redistribute to the cytosol, a process that was typically complete 5 min after gametocyte activation. A quantitative analysis in randomly selected macrogametocytes found that CFP–PH–YFP redistributed to the cytosol in about half of the cells. A few cells showed a high proportion of peripherally located CFP–PH–YFP that did not change upon activation; these cells may have been immature gametocytes still unable to be activated. Other gametocytes had a relatively high level of cytosolic fluorescence that remained unchanged.The latter response was typical of the cytosolic localization in the control cell line expressing GFP without a PH domain. CFP–PH–YFP expressing cells with  cytosolic localization of the marker may have responded already during the minute that typically elapsed between gametocyte activation and recording of the first image. Male and female gametocytes both showed redistribution of the CFP–PH–YFP reporter constructs, but due to the choice of promoter the reporter protein was more strongly expressed and easier to detect in female gametocytes.

Additional information

Other mutants


  Transgene: Mutant parasite expressing a transgene
Type and details of transgene
Is the transgene Plasmodium derived Transgene: not Plasmodium
Transgene namePH domain of human phospholipase Cδ1 (hPLCδ1) fused to YFP and CFP
Details of the genetic modification
Inducable system usedNo
Additional remarks inducable system
Type of plasmid/constructCircular plasmid
PlasmoGEM (Sanger) construct/vector usedNo
Modified PlasmoGEM construct/vector usedNo
Plasmid/construct map
Plasmid/construct sequence
Restriction sites to linearize plasmid
Selectable marker used to select the mutant parasitetgdhfr
Promoter of the selectable markerpbdhfr
Selection (positive) procedurepyrimethamine
Selection (negative) procedureNo
Additional remarks genetic modificationThe mutant expresses a fusion protein consisting of the PH domain of human phospholipase Cδ1 (hPLCδ1) fused to yellow fluorescent protein (YFP) and cyan fluorescent protein (CFP).

A P. berghei expression cassette was generated, in which the strong constitutive eef1α promoter controls expression of a fusion protein consisting of the PH domain of hPLCδ1 fused to YFP (C-terminal) and CFP (N-terminal). A vector containing this reporter cassette, together with a tgdhfr/ts selection marker for antimalarial drug resistance, was then introduced into P. berghei schizonts by electroporation, and maintained as episome by selecting for the resistance marker.

The PH domain of human phospholipase Cδ1 (hPLCδ1) fused to CFP and YFP was isolated from a pcDNA3.1(+)-based plasmid containing the CYPHR fusion protein (Violin et al., 2003) as a HindIII/XbaI fragment and subsequently blunted. The P. berghei expression vector pDEFGFPM3A encodes the green fluorescent protein (GFP) and is equivalent to MR4 reagent MRA-786 (pL0017) differing from the pPbGFPCON (Franke-Fayard et al., 2004) only by the presence of an additional XbaI site immediately following the stop codon of gfp. The gfp coding sequence was removed by a BamHI/XbaI digest, the vector blunted and the CFP–PH–YFP sequence inserted.
Additional remarks selection procedure
Other details transgene
Promoter
Gene Model of Parasite PBANKA_1133300
Gene Model P. falciparum ortholog PF3D7_1357100
Gene productelongation factor 1-alpha
Gene product: Alternative nameeef1a
Primer information details of the primers used for amplification of the promoter sequence  Click to view information
Primer information details of the primers used for amplification of the promoter sequence  Click to hide information
Sequence Primer 1
Additional information primer 1
Sequence Primer 2
Additional information primer 2
3'-UTR
Gene Model of Parasite PBANKA_0719300
Gene productbifunctional dihydrofolate reductase-thymidylate synthase, putative
Gene product: Alternative namedhfr/ts
Primer information details of the primers used for amplification the 3'-UTR sequences  Click to view information
Primer information details of the primers used for amplification the 3'-UTR sequences  Click to hide information
Sequence Primer 1
Additional information primer 1
Sequence Primer 2
Additional information primer 2
Insertion/Replacement locus
Replacement / InsertionNot available
Gene Model of Parasite Not available
Gene productNot available
Gene product: Alternative name
Primer information details of the primers used for amplification of the target sequences  Click to view information
Primer information details of the primers used for amplification of the target sequences  Click to hide information
Sequence Primer 1
Additional information primer 1
Sequence Primer 2
Additional information primer 2
Sequence Primer 3
Additional information primer 3
Sequence Primer 4
Additional information primer 4