RMgmDB - Rodent Malaria genetically modified Parasites

Summary

RMgm-5091
Malaria parasiteP. berghei
Genotype
TaggedGene model (rodent): PBANKA_1122000; Gene model (P.falciparum): PF3D7_0623100; Gene product: nuclear polyadenylated RNA-binding protein NAB2, putative (nab2)
Name tag: mCherry
Phenotype Asexual bloodstage;
Last modified: 26 October 2021, 17:41
  *RMgm-5091
Successful modificationThe parasite was generated by the genetic modification
The mutant contains the following genetic modification(s) Gene tagging
Reference (PubMed-PMID number) Reference 1 (PMID number) : 34604117
MR4 number
Parent parasite used to introduce the genetic modification
Rodent Malaria ParasiteP. berghei
Parent strain/lineP. berghei ANKA
Name parent line/clone Not applicable
Other information parent line
The mutant parasite was generated by
Name PI/ResearcherNiikura M, Kobayashi F
Name Group/DepartmentDepartment of Environmental Science, School of Life and Environmental Science
Name InstituteAzabu University
CityKanagawa
CountryJapan
Name of the mutant parasite
RMgm numberRMgm-5091
Principal nameNAB2::mCherry
Alternative name
Standardized name
Is the mutant parasite cloned after genetic modificationYes
Phenotype
Asexual blood stageTo examine the cellular localization of NAB2, we performed live-cell fluorescence imaging of cultured NAB2::mCherry schizonts and infected erythrocytes obtained from mice at 6 h (ring form), 12 h (trophozoite) and 18 h (late trophozoite) post-inoculation with NAB::mCherry schizonts

In NAB2::mCherry parasites, a single fluorescent spot representing the mCherry signal was present at the nuclear periphery in cultured schizonts and schizont-infected erythrocytes collected at 6 h (ring form) post-inoculation. At 12 h (trophozoite) and 18 h (late trophozoite) post-inoculation, speckled mCherry signals were present at the nuclear periphery in NAB2::mCherry cells. A spot of mCherry fluorescence was also detected in the cytoplasm of NAB2::mCherry parasites at 18 h (late trophozoite) post-inoculation.
Gametocyte/GameteNot tested
Fertilization and ookineteNot tested
OocystNot tested
SporozoiteNot tested
Liver stageNot tested
Additional remarks phenotype

Mutant/mutation
The mutant  expresses a C-terminal mCherry-tagged version of NAB2. The mCherry tag was introduced at the C-terminus of endogenous NAB2. Nab2::mCherry expression was controlled by the endogenous nab2 native promoters.

Protein (function)
Nuclear poly(A) binding protein 2 (NAB2), THO complex subunit 4 (THO4), nucleolar protein 3 (NPL3), G-strand binding protein 2 (GBP2) and serine/arginine-rich splicing factor 1 (SR1) are involved in nuclear mRNA export in malaria parasites.

NAB2 contains an N-terminal PWI domain and a C-terminal CCCH-type zinc finger motif, similar to yeast NAB2. Moreover, a nuclear localization signal (NLS), RX2–5PY NLS (PY-NLS), is present in NAB2

Phenotype
To examine the cellular localization of NAB2, we performed live-cell fluorescence imaging of cultured NAB2::mCherry schizonts and infected erythrocytes obtained from mice at 6 h (ring form), 12 h (trophozoite) and 18 h (late trophozoite) post-inoculation with NAB::mCherry schizonts. 
In NAB2::mCherry parasites, a single fluorescent spot representing the mCherry signal was present at the nuclear periphery in cultured schizonts and schizont-infected erythrocytes collected at 6 h (ring form) post-inoculation. At 12 h (trophozoite) and 18 h (late trophozoite) post-inoculation, speckled mCherry signals were present at the nuclear periphery in NAB2::mCherry cells. A spot of mCherry fluorescence was also detected in the cytoplasm of NAB2::mCherry parasites at 18 h (late trophozoite) post-inoculation..  

Additional information
To determine whether NAB2 localizes to the inside of the nuclear membrane in malaria parasites, we generated a NAB2::mCherry strain expressing NUP205 (nucleopore protein) fused to green fluorescent protein (GFP). Because NUP205 fluorescence increases with the size of the nucleus in P. berghei, we analyzed parasites during the late trophozoite stage (18 h post-inoculation). Live-cell fluorescence imaging revealed that the GFP signal was localized mainly to the nuclear periphery in P. berghei ANKA trophozoites, implying that NAB2 localized to the inner nuclear membrane in P. berghei  ANKA. To investigate whether the fluorescent signal of mCherry detected in the cytoplasm represented localization to mitochondria, NAB2::mCherry parasites were stained with mitotracker; the mCherry signal did not overlap that of mitochondria.

To investigate which proteins interact with NAB2, we performed protein IP using anti-mCherry beads and identified the proteins bound to NAB2 by MS. 
To identify RNAs bound by NAB2 ,we performed RIPseq on mature schizonts- and gametocytes-lysates using anti-mCherry beads and sequenced the RNAs bound to NAB2. No SR1-binding mRNAs  were detected by RIPseq of NAB2. Moreover, no SR1 homologues were detected by IP-MS of NAB2. No nuclear pore complex proteins or  export receptor-like proteins were detected by IP-MS of NAB2::mCherry. 

Other mutants


  Tagged: Mutant parasite with a tagged gene
Details of the target gene
Gene Model of Rodent Parasite PBANKA_1122000
Gene Model P. falciparum ortholog PF3D7_0623100
Gene productnuclear polyadenylated RNA-binding protein NAB2, putative
Gene product: Alternative namenab2
Details of the genetic modification
Name of the tagmCherry
Details of taggingC-terminal
Additional remarks: tagging
Commercial source of tag-antibodies
Type of plasmid/construct(Linear) plasmid double cross-over
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 parasitehdhfr
Promoter of the selectable markereef1a
Selection (positive) procedurepyrimethamine
Selection (negative) procedureNo
Additional remarks genetic modificationTo generate transgenic parasites expressing mCherry-fused GBP2 or mCherry-fused NAB2, the gene-targeting vectors for gbp2 (PBANKA_120500) or nab2 (PBANKA_1122000) were prepared by PCR. The PCR products were annealed to either side of the red fluorescent protein gene (mCherry)-hdhfr expressing cassette and amplified by PCR using gene-specific primers. The gene targeting vectors were introduced into the 3’ flanking regions of ORFs of target genes by double-crossover homologous recombination
Additional remarks selection procedure
Primer information: Primers used for amplification of the target sequences  Click to view information
Primer information: 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
Sequence Primer 5
Additional information primer 5
Sequence Primer 6
Additional information primer 6