PTP5

PF3D7_1002100 · EMP1-trafficking protein

Annotated: 2026-09-08

95 papers in source corpus 2 papers cited in narrative 2 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

PTP5 (PF3D7_1002100) is an exported Plasmodium falciparum protein that functions in host erythrocyte remodeling, specifically in the trafficking of the virulence adhesin PfEMP1 to the infected red-cell surface and in knob assembly; knockout of PTP5 abolishes both PfEMP1 export and knob formation, placing it among the parasite's essential host-cell remodeling machinery (PMID:18614010). PTP5 export from the parasite into the host erythrocyte cytosol depends on a direct interaction with the parasitophorous vacuole dense granule protein PfPV1, mediated by a C-terminal PfPV1 High-affinity Region (PHR) on PTP5; deletion of the PHR arrests PTP5 export, establishing this interaction as necessary for PTP5's own delivery into the host cell (PMID:29487358). Beyond its role in PfEMP1 trafficking, knob assembly, and its PfPV1-dependent export, no further mechanistic detail for PTP5 has been characterized in the available corpus.

Mechanistic history

Synthesis pass · year-by-year structured walk · 2 steps

2008 Medium
Establishing whether PTP5 is functionally required for the parasite's export of its major virulence adhesin, this work showed PTP5 is one of the exported factors whose loss abolishes PfEMP1 surface trafficking and knob formation.

Evidence Large-scale gene knockout with PfEMP1 export and knob assembly functional readouts in P. falciparum

PMID:18614010
Open questions at the time
- Does not define the molecular step at which PTP5 acts in the trafficking pathway
- No direct binding partners or biochemical activity identified
- Whether PTP5 acts on PfEMP1 directly or indirectly is unresolved
2018 High
Addressing how PTP5 itself reaches the host cytosol, this work identified a direct PTP5–PfPV1 interaction via a C-terminal PHR and showed the PHR is required for PTP5 export, linking parasitophorous vacuole PfPV1 to PTP5 trafficking.

Evidence Co-immunoprecipitation, surface plasmon resonance, deletion mutagenesis, and structured illumination microscopy of an export-arrested PTP5ΔPHR mutant in P. falciparum

PMID:29487358
Open questions at the time
- Structural basis of the PHR–PfPV1 interaction is not resolved
- Whether PfPV1 binding to PTP5 is required downstream for PfEMP1 trafficking specifically is not shown
- Mechanism connecting PTP5 export to knob assembly remains undefined

Open questions

Synthesis pass · forward-looking unresolved questions

The molecular activity of PTP5 within the PfEMP1 trafficking pathway — including any direct cargo binding, its interactors in the host cytosol, and how it contributes to knob assembly — remains unknown.
No direct PTP5–PfEMP1 interaction demonstrated
No structural model of PTP5
No definition of PTP5's biochemical role in knob assembly

Mechanism profile

Synthesis pass · controlled-vocabulary classification

Partners

PFEMP1 (FUNCTIONALLY REQUIRED FOR ITS EXPORT; DIRECT INTERACTION NOT ESTABLISHED) [#0]PFPV1 (PARASITOPHOROUS VACUOLE DENSE GRANULE PROTEIN; DIRECT BINDING VIA PTP5 C-TERMINAL PHR) [#1]

Evidence

Reading pass · 2 per-paper findings extracted from the source corpus

Year	Finding	Method	Journal	Conf	PMIDs
2008	PTP5 (PF3D7_1002100) was identified as one of eight exported proteins required for trafficking of PfEMP1 to the infected erythrocyte surface and for assembly of knobs; knockout of PTP5 abolished PfEMP1 export and knob formation, establishing its role as a component of the parasite's host-cell remodeling machinery.	Large-scale gene knockout combined with functional screens (PfEMP1 export assay, knob assembly assay) in P. falciparum	Cell	Medium	18614010
2018	PTP5 directly interacts with PfPV1 (a merozoite dense granule protein localized to the parasitophorous vacuole): co-immunoprecipitation with anti-PfPV1 antibody pulled down PTP5, and surface plasmon resonance confirmed direct protein-protein interaction. A C-terminal region of PTP5 designated the PfPV1 High-affinity Region (PHR) was identified as the dominant binding site. A PTP5 mutant lacking PHR (PTP5ΔPHR) showed arrested export to the infected erythrocyte cytosol, indicating PHR is essential for PTP5 export.	Co-immunoprecipitation, surface plasmon resonance (SPR), structured illumination microscopy (SIM) of export-arrested mutant, deletion mutagenesis	Scientific reports	High	29487358

Source papers

Stage 0 corpus · 95 papers · ranked by NIH iCite citations

Year	Title	Journal	Citations	PMID
2008	Exported proteins required for virulence and rigidity of Plasmodium falciparum-infected human erythrocytes.	Cell	410	18614010
2008	Antigenic variation in Plasmodium falciparum.	Annual review of microbiology	338	18785843
2000	Classification of adhesive domains in the Plasmodium falciparum erythrocyte membrane protein 1 family.	Molecular and biochemical parasitology	224	11071284
2012	Plasmodium falciparum erythrocyte membrane protein 1 domain cassettes 8 and 13 are associated with severe malaria in children.	Proceedings of the National Academy of Sciences of the United States of America	222	22619319
2006	A family affair: var genes, PfEMP1 binding, and malaria disease.	Current opinion in microbiology	221	16814594
2009	Sir2 paralogues cooperate to regulate virulence genes and antigenic variation in Plasmodium falciparum.	PLoS biology	199	19402747
2013	Malaria's deadly grip: cytoadhesion of Plasmodium falciparum-infected erythrocytes.	Cellular microbiology	179	23957661
2017	Variant surface antigens of Plasmodium falciparum and their roles in severe malaria.	Nature reviews. Microbiology	171	28603279
2003	Cytoadherence and sequestration in Plasmodium falciparum: defining the ties that bind.	Microbes and infection	157	12919858
2017	Structure-Guided Identification of a Family of Dual Receptor-Binding PfEMP1 that Is Associated with Cerebral Malaria.	Cell host & microbe	154	28279348
2015	PfEMP1 - A Parasite Protein Family of Key Importance in Plasmodium falciparum Malaria Immunity and Pathogenesis.	Advances in parasitology	137	25911365
2000	Molecular aspects of severe malaria.	Clinical microbiology reviews	125	10885986
2014	Surface antigens of Plasmodium falciparum-infected erythrocytes as immune targets and malaria vaccine candidates.	Cellular and molecular life sciences : CMLS	120	24691798
2012	Plasmodium falciparum-encoded exported hsp70/hsp40 chaperone/co-chaperone complexes within the host erythrocyte.	Cellular microbiology	119	22925632
1999	Mapping the binding domains involved in the interaction between the Plasmodium falciparum knob-associated histidine-rich protein (KAHRP) and the cytoadherence ligand P. falciparum erythrocyte membrane protein 1 (PfEMP1).	The Journal of biological chemistry	117	10446142
2019	Cerebral Plasmodium falciparum malaria: The role of PfEMP1 in its pathogenesis and immunity, and PfEMP1-based vaccines to prevent it.	Immunological reviews	109	31562653
2008	PfEMP1: an antigen that plays a key role in the pathogenicity and immune evasion of the malaria parasite Plasmodium falciparum.	The international journal of biochemistry & cell biology	107	19150410
2012	A novel domain cassette identifies Plasmodium falciparum PfEMP1 proteins binding ICAM-1 and is a target of cross-reactive, adhesion-inhibitory antibodies.	Journal of immunology (Baltimore, Md. : 1950)	103	23209327
2017	Linking EPCR-Binding PfEMP1 to Brain Swelling in Pediatric Cerebral Malaria.	Cell host & microbe	95	29107642
2013	Plasmodium nesting: remaking the erythrocyte from the inside out.	Annual review of microbiology	89	23808341
2010	Surface co-expression of two different PfEMP1 antigens on single plasmodium falciparum-infected erythrocytes facilitates binding to ICAM1 and PECAM1.	PLoS pathogens	89	20824088
2001	Decoding the language of var genes and Plasmodium falciparum sequestration.	Trends in parasitology	84	11872399
2004	var genes, PfEMP1 and the human host.	Molecular and biochemical parasitology	83	14747137
2018	Remodeling of the malaria parasite and host human red cell by vesicle amplification that induces artemisinin resistance.	Blood	82	29363540
2007	PfEMP1-DBL1alpha amino acid motifs in severe disease states of Plasmodium falciparum malaria.	Proceedings of the National Academy of Sciences of the United States of America	78	17895392
2016	Plasmodium falciparum var genes expressed in children with severe malaria encode CIDRα1 domains.	EMBO molecular medicine	77	27354391
2017	Parasites Causing Cerebral Falciparum Malaria Bind Multiple Endothelial Receptors and Express EPCR and ICAM-1-Binding PfEMP1.	The Journal of infectious diseases	71	28863469
2014	A Plasmodium falciparum PHIST protein binds the virulence factor PfEMP1 and comigrates to knobs on the host cell surface.	FASEB journal : official publication of the Federation of American Societies for Experimental Biology	69	24983468
2014	The role of PfEMP1 adhesion domain classification in Plasmodium falciparum pathogenesis research.	Molecular and biochemical parasitology	68	25064606
2009	The role of platelets in the pathogenesis of cerebral malaria.	Cellular and molecular life sciences : CMLS	67	20091081
2018	Extracellular vesicles from early stage Plasmodium falciparum-infected red blood cells contain PfEMP1 and induce transcriptional changes in human monocytes.	Cellular microbiology	65	29349926
2017	The Severity of Plasmodium falciparum Infection Is Associated with Transcript Levels of var Genes Encoding Endothelial Protein C Receptor-Binding P. falciparum Erythrocyte Membrane Protein 1.	Infection and immunity	64	28138022
2017	Red blood cells release microparticles containing human argonaute 2 and miRNAs to target genes of Plasmodium falciparum.	Emerging microbes & infections	64	28831191
2013	Spatial and temporal mapping of the PfEMP1 export pathway in Plasmodium falciparum.	Cellular microbiology	62	23421990
2009	High throughput functional assays of the variant antigen PfEMP1 reveal a single domain in the 3D7 Plasmodium falciparum genome that binds ICAM1 with high affinity and is targeted by naturally acquired neutralizing antibodies.	PLoS pathogens	61	19381252
2013	How malaria modulates memory: activation and dysregulation of B cells in Plasmodium infection.	Trends in parasitology	59	23562778
2007	Haemoglobin C and S role in acquired immunity against Plasmodium falciparum malaria.	PloS one	59	17912355
2006	Programmed transcription of the var gene family, but not of stevor, in Plasmodium falciparum gametocytes.	Eukaryotic cell	59	16896206
2012	Abnormal PfEMP1/knob display on Plasmodium falciparum-infected erythrocytes containing hemoglobin variants: fresh insights into malaria pathogenesis and protection.	Microbes and infection	56	22634344
2021	Afucosylated Plasmodium falciparum-specific IgG is induced by infection but not by subunit vaccination.	Nature communications	54	34611164
2010	The role of Plasmodium falciparum variant surface antigens in protective immunity and vaccine development.	Human vaccines	53	19823032
2008	Default Pathway of var2csa switching and translational repression in Plasmodium falciparum.	PloS one	53	18431472
2001	Parasite adhesion and immune evasion in placental malaria.	Trends in parasitology	52	11423376
2003	Plasmodium falciparum adhesion in the placenta.	Current opinion in microbiology	51	12941407
2015	α2-Macroglobulin Can Crosslink Multiple Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1) Molecules and May Facilitate Adhesion of Parasitized Erythrocytes.	PLoS pathogens	50	26134405
2017	The exported chaperone Hsp70-x supports virulence functions for Plasmodium falciparum blood stage parasites.	PloS one	49	28732045
2012	α-Thalassemia impairs the cytoadherence of Plasmodium falciparum-infected erythrocytes.	PloS one	48	22623996
2004	Immunization with PfEMP1-DBL1alpha generates antibodies that disrupt rosettes and protect against the sequestration of Plasmodium falciparum-infected erythrocytes.	Vaccine	48	15246600
2006	Characterization of anti-var2CSA-PfEMP1 cytoadhesion inhibitory mouse monoclonal antibodies.	Microbes and infection	46	17095277
2016	The role of PfEMP1 as targets of naturally acquired immunity to childhood malaria: prospects for a vaccine.	Parasitology	45	26741401
2007	Dissection of the role of PfEMP1 and ICAM-1 in the sensing of Plasmodium-falciparum-infected erythrocytes by natural killer cells.	PloS one	45	17311092
2011	Immunisation with recombinant PfEMP1 domains elicits functional rosette-inhibiting and phagocytosis-inducing antibodies to Plasmodium falciparum.	PloS one	43	21305024
2004	The microcirculation in severe malaria.	Microcirculation (New York, N.Y. : 1994)	43	15513866
2011	var gene transcription and PfEMP1 expression in the rosetting and cytoadhesive Plasmodium falciparum clone FCR3S1.2.	Malaria journal	40	21266056
2011	TLRs innate immunereceptors and Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) CIDR1α-driven human polyclonal B-cell activation.	Acta tropica	40	21620790
2017	Three Is a Crowd - New Insights into Rosetting in Plasmodium falciparum.	Trends in parasitology	38	28109696
2019	Cholesterol bound Plasmodium falciparum co-chaperone 'PFA0660w' complexes with major virulence factor 'PfEMP1' via chaperone 'PfHsp70-x'.	Scientific reports	37	30804381
2001	Molecular mechanisms of Plasmodium falciparum placental adhesion.	Cellular microbiology	37	11260135
2011	Antibodies against PfEMP1, RIFIN, MSP3 and GLURP are acquired during controlled Plasmodium falciparum malaria infections in naïve volunteers.	PloS one	35	22174947
2013	Plasmodium falciparum expressing domain cassette 5 type PfEMP1 (DC5-PfEMP1) bind PECAM1.	PloS one	34	23874884
2002	Human complement receptor type 1 (CR1) binds to a major malarial adhesin.	Trends in molecular medicine	34	12421687
2017	Population genomics of virulence genes of Plasmodium falciparum in clinical isolates from Uganda.	Scientific reports	33	28924231
2010	Of mice and women: rodent models of placental malaria.	Trends in parasitology	33	20605743
2002	Recombinant PfEMP1 peptide inhibits and reverses cytoadherence of clinical Plasmodium falciparum isolates in vivo.	Blood	32	12393525
2012	Multilaboratory approach to preclinical evaluation of vaccine immunogens for placental malaria.	Infection and immunity	31	23208604
2019	Evasion of Classical Complement Pathway Activation on Plasmodium falciparum-Infected Erythrocytes Opsonized by PfEMP1-Specific IgG.	Frontiers in immunology	30	30666256
2017	Structural analysis of P. falciparum KAHRP and PfEMP1 complexes with host erythrocyte spectrin suggests a model for cytoadherent knob protrusions.	PLoS pathogens	30	28806784
2010	Protein export in Plasmodium parasites: from the endoplasmic reticulum to the vacuolar export machine.	International journal for parasitology	30	20170656
2005	Clinical and molecular aspects of severe malaria.	Anais da Academia Brasileira de Ciencias	30	16127552
2018	Natural and Vaccine-Induced Acquisition of Cross-Reactive IgG-Inhibiting ICAM-1-Specific Binding of a Plasmodium falciparum PfEMP1 Subtype Associated Specifically with Cerebral Malaria.	Infection and immunity	29	29426042
2017	Regulation of PfEMP1-VAR2CSA translation by a Plasmodium translation-enhancing factor.	Nature microbiology	29	28481333
2007	Structural basis for binding of Plasmodium falciparum erythrocyte membrane protein 1 to chondroitin sulfate and placental tissue and the influence of protein polymorphisms on binding specificity.	The Journal of biological chemistry	29	17562715
2021	Common virulence gene expression in adult first-time infected malaria patients and severe cases.	eLife	28	33908865
2018	PV1, a novel Plasmodium falciparum merozoite dense granule protein, interacts with exported protein in infected erythrocytes.	Scientific reports	28	29487358
2017	Plasmodium falciparum PfEMP1 Modulates Monocyte/Macrophage Transcription Factor Activation and Cytokine and Chemokine Responses.	Infection and immunity	28	29038124
2024	Broadly inhibitory antibodies to severe malaria virulence proteins.	Nature	21	39567685
2024	PfEMP1 and var genes - Still of key importance in Plasmodium falciparum malaria pathogenesis and immunity.	Advances in parasitology	14	39095112
2025	Variable surface antigen expression, virulence, and persistent infection by Plasmodium falciparum malaria parasites.	Microbiology and molecular biology reviews : MMBR	9	39807932
2024	Antibodies to PfEMP1 and variant surface antigens: Protection after controlled human malaria infection in semi-immune Kenyan adults.	The Journal of infection	8	39182654
2025	Acquisition of Fc-afucosylation of PfEMP1-specific IgG is age-dependent and associated with clinical protection against malaria.	Nature communications	6	39747065
2025	Fc-Afucosylation of VAR2CSA-Specific Immunoglobulin G and Clinical Immunity to Placental Plasmodium falciparum Malaria.	The Journal of infectious diseases	5	39585195
2025	Plasmodium falciparum expresses fewer var genes at lower levels during asymptomatic dry season infections than clinical malaria cases.	PLoS pathogens	5	40493675
2025	Identification of broadly inhibitory anti-PfEMP1 antibodies by mass spectrometry sequencing of plasma IgG from a malaria-exposed child.	Proceedings of the National Academy of Sciences of the United States of America	5	40833410
2025	A paradoxical population structure of var DBLα types in Africa.	PLoS pathogens	4	39903780
2025	Immune evasion runs in the family: two surface protein families of Plasmodium falciparum-infected erythrocytes.	Current opinion in microbiology	4	40112571
2025	A system for functional studies of the major virulence factor of malaria parasites.	eLife	3	41460168
2025	Identification of novel PfEMP1 variants containing domain cassettes 11, 15 and 8 that mediate the Plasmodium falciparum virulence-associated rosetting phenotype.	PLoS pathogens	2	39804943
2025	Var genes, strain hyperdiversity, and malaria transmission dynamics.	Trends in parasitology	2	40393890
2025	The role of periostin (OSF-2) in the cytoadherence phenomena mediated by malaria parasites.	Frontiers in cellular and infection microbiology	2	40433670
2025	Computational Drug Repositioning for Targeting PfEMP1: Potential Therapeutics for Cerebral Malaria in Plasmodium falciparum.	Biotechnology and applied biochemistry	2	40808285
2025	Breaking the bind: PfEMP1-specific antibodies in cerebral malaria.	Frontiers in immunology	2	41246335
2025	A monoclonal antibody selectively recognizing PfEMP1 proteins associated with cerebral malaria.	Scientific reports	1	41053123
2026	Febrile Temperature Augments Ring-stage Plasmodium falciparum Adhesion to Brain Endothelial Cells.	The Journal of infectious diseases	0	40929367
2026	Mechanistic insights into coordinated var transcriptional switching in malaria parasites.	The EMBO journal	0	41851501
2026	Predictive value of PfEMP1 antibody profiles for the course of controlled human malaria infections.	PLoS pathogens	0	42341059