RMgmDB - Rodent Malaria genetically modified Parasites

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Summary

RMgm-1499
Malaria parasiteP. berghei
Genotype
Transgene
Transgene Plasmodium: Gene model: PBANKA_1464100; Gene model (P.falciparum): PF3D7_1251200; Gene product: coronin
Promoter: Gene model: PBANKA_1400800; Gene model (P.falciparum): PF3D7_1302200; Gene product: early transcribed membrane protein 13 (UIS3; up-regulated in infective sporozoites; ETRAMP13)
3'UTR: Gene model: PBANKA_0719300; Gene product: bifunctional dihydrofolate reductase-thymidylate synthase, putative (dhfr/ts)
Insertion locus: Gene model: PBANKA_1400800; Gene product: early transcribed membrane protein 13 (UIS3; up-regulated in infective sporozoites; ETRAMP13)
Phenotype Oocyst; Sporozoite;
Last modified: 18 July 2016, 17:47
  *RMgm-1499
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) : 27409081
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/ResearcherBane KS; Frischknecht F
Name Group/DepartmentIntegrative Parasitology, Center for Infectious Diseases
Name InstituteUniversity of Heidelberg Medical School
CityHeidelberg
CountryGermany
Name of the mutant parasite
RMgm numberRMgm-1499
Principal nameUIS3-Cor-mCh
Alternative name
Standardized name
Is the mutant parasite cloned after genetic modificationYes
Phenotype
Asexual blood stageNot different from wild type
Gametocyte/GameteNot different from wild type
Fertilization and ookineteNot different from wild type
OocystCoronin-mCherry expression in midgut and salivary gland sporozoites. In sporozoites isolated from oocysts and in those isolated from salivary glands, the fluorescent signal localized to the periphery of the parasite.
SporozoiteCoronin-mCherry expression in midgut and salivary gland sporozoites. In sporozoites isolated from oocysts and in those isolated from salivary glands, the fluorescent signal localized to the periphery of the parasite.
Liver stageNot different from wild type
Additional remarks phenotype

Mutant/mutation
The mutant expresses of C-terminal mCherry-tagged version of coronin introduced in the uis3 gene locus. The coronin gene is under control of the uis3 promoter.

Protein (function)
From the paper:
The motor driving this gliding motility is located underneath the plasma membrane in a narrow space delimited by a membrane organelle called the inner membrane complex (IMC) that subtends the plasma membrane at a distance of approximately 30nm. Within this space, it is thought that myosin, anchored in the IMC, drives actin filaments rearwards in what resembles retrograde flow. Actin filaments themselves are likely linked to transmembrane proteins that contain adhesive domains including an integrin-like Adomain. This linkage thus drives parasite motility upon attachment to a substrate although it is not clear how the different transmembrane proteins transmit force. Actin filaments are extremely short in Plasmodium as well as in related parasites and cannot be routinely visualized. This is at least partly due to a number of differences in the actin monomer structure that prevent the formation of long filaments. In addition, actin binding proteins might play a role in regulating actin filament dynamics.
The Plasmodium genome only encodes a small set of canonical actin-binding proteins. The only bona-fide actin filament-binding protein in the Plasmodium genome is coronin, which shares only 31% sequence identity to Dictyostelium coronin. Coronin is conserved among the different species of Plasmodium and shows 57% identity between the major human malaria-causing parasite P. falciparum and the rodent model parasite P. berghei Coronins are a family of actin filament-binding proteins with the first identified coronin described to be important for cell motility and differentiation in Dictyostelium discoidum. All coronins have one or twoWD40 repeat-containing ß-propellers that mediate actin filament-binding. Coronins can harbor 2 independent actin-binding sites in their ß-propellers and can also bind membranes. Furthermore, coronins can contain a number of additional domains and regions that allow dimer formation and interaction with a range of different proteins including actin-binding proteins and microtubules. In alveolata, a major superphylum of protists, coronins belong to the orphan class of short coronins containing one ß-propeller. Coronin has been examined in several protozoan parasites such as the human malaria-causing parasite Plasmodium falciparum, the related apicomplexan parasite Toxoplasma gondii and in Leishmania, unicellular parasites from the excavata branch. Yet the coronins in each of these organisms display divergent functions. While in Leishmania coronin is essential for microtubule organization, in Toxoplasma gondii it only binds actin filaments weakly and plays a minor, uncharacterized role during host cell invasion. In P. falciparum coronin was identified and characterized as an actin filament-binding protein and shown to be able to bind to membranes and bundle actin filaments. These functional differences might be explained by the divergence of coronin among these organisms.

Phenotype

Phenotype analyses of a mutant lacking expression of coronin (RMgm-1497) showed the following:
Normal numbers of midgut sporozoites are formed. Significantly lower numbers (60-70%) of coronin(-) sporozoites accumulate in the salivary glands. Evidence is presented for a (slightly) reduced liver stage development. Coronin(-) sporozoites show aberrant motility. However, no evidence was found for a defect in migration in the skin.

Phenotype analyses of the mutants that expresses an mCherry-tagged coronin showed the following:
Coronin-mCherry expression in midgut and salivary gland sporozoites. In sporozoites isolated from oocysts and in those isolated from salivary glands, the fluorescent signal localized to the periphery of the parasite.
When bovine serum albumin, which stimulates motility, was added to the salivary gland derived sporozoites, coronin-mCherry relocalized to the rear of the now migrating parasite.
Eveidence is presented that coronin localizes to the rear of motile sporozoites in an actin dependent manner.

See also mutant RMgm-1498 that expresses an mCherry-tagged coronin. In this mutant the endogenous gene has been tagged with mCherry.

Additional information
A number of mutants have been generated expressing mutated forms of coronin. Analyses of these mutants provided evidence for that coronin show distinct binding to membranes and actin filaments and that mutants with mutated coronins exhibit defects in sporozoite motility.

From the paper:
Here we generated a series of parasite lines that either lack coronin, contain mutations of important residues in the ß-propeller or express coronin fused to mCherry in P. berghei, a rodent model parasite. These lines show that P. berghei coronin localizes to the sporozoite periphery in a calcium dependent but actin independent manner and actively contributes to parasite motility through actin filament-binding. During the rapid onset of migration extracellular ligands first trigger intracellular calcium release prior to actin filament formation and coronin relocalization to the rear of the gliding sporozoite. Importantly, coronin is required for efficient transmission of the parasite from mosquitoes to mice as coronin(-) parasites and parasites expressing mutated coronin show defects in salivary gland invasion.
 
Other mutants
See the link PF3D7_1251200 for other related mutants


  Transgene: Mutant parasite expressing a transgene
Type and details of transgene
Is the transgene Plasmodium derived Transgene: Plasmodium
Gene Model of Parasite PBANKA_1464100
Gene Model P. falciparum ortholog PF3D7_1251200
Gene productcoronin
Gene product: Alternative name
Details of the genetic modification
Inducable system usedNo
Additional remarks inducable system
Type of plasmid/construct(Linear) plasmid single 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 parasitetgdhfr
Promoter of the selectable markerpbdhfr
Selection (positive) procedurepyrimethamine
Selection (negative) procedureNo
Additional remarks genetic modificationThe mutant expresses of C-terminal mCherry-tagged version of coronin introduced in the uis3 gene locus. The coronin gene is under control of the uis3 promoter.
Additional remarks selection procedure
Other details transgene
Promoter
Gene Model of Parasite PBANKA_1400800
Gene Model P. falciparum ortholog PF3D7_1302200
Gene productearly transcribed membrane protein 13
Gene product: Alternative nameUIS3; up-regulated in infective sporozoites; ETRAMP13
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 / InsertionInsertion locus
Gene Model of Parasite PBANKA_1400800
Gene productearly transcribed membrane protein 13
Gene product: Alternative nameUIS3; up-regulated in infective sporozoites; ETRAMP13
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