Affinage · Plasmodium

Showing PF3D7_0527500 — PBANKA_1242300 is a PlasmoDB ID.

HIP

PF3D7_0527500 · Hsc70-interacting protein

Audit flag: identity unverified
Annotated
2026-09-07
5 papers in source corpus 2 papers cited in narrative 2 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

PF3D7_0527500 (HIP) is a Plasmodium falciparum Hsp70-interacting co-chaperone that enhances the ATP-dependent chaperone activity of the Hsp70 chaperones PfHsp70-1 (which carries the C-terminal EEVD motif) and PfHsp70-2 (PMID:16884692). Its substrate-binding activity is not blocked by the antimalarial compound 15-deoxyspergualin (DSG) (PMID:16884692). A separate HSC70-associated complex containing 32/34-kDa proteins from P. knowlesi merozoites caps actin filaments and inhibits actin polymerization in a calcium-independent, PIP2-sensitive manner, but the identity of those 32/34-kDa proteins as PF3D7_0527500 was not established, so this activity cannot be assigned to HIP itself (PMID:9662713). Beyond its role as an Hsp70 co-chaperone (PMID:16884692), no further mechanistic detail for PF3D7_0527500 has been characterized in the available corpus.

Mechanistic history

Synthesis pass · year-by-year structured walk · 2 steps
  1. 2006 Medium

    To establish what PF3D7_0527500 does biochemically, it was tested for direct effects on Hsp70 function, showing it is a co-chaperone that potentiates Hsp70 chaperone activity in P. falciparum.

    Evidence cloning, overexpression, and in vitro chaperone activity assay with defined Hsp70 substrates, +/- ATP and DSG

    PMID:16884692

    Open questions at the time
    • single-lab in vitro reconstitution not confirmed in cellulo or in vivo
    • structural basis of the HIP-Hsp70 interaction not defined
    • physiological substrates handed off by the HIP/Hsp70 pair not identified
  2. 1998 Low

    Whether an HSC70-associated 32/34-kDa protein complex regulates the merozoite actin cytoskeleton was tested, showing filament-capping and polymerization-inhibiting activity, but the complex was not confirmed to contain PF3D7_0527500.

    Evidence F-actin affinity and ATP-agarose chromatography, gel filtration, in vitro actin polymerization assay, and tryptic peptide microsequencing in P. knowlesi merozoites

    PMID:9662713

    Open questions at the time
    • identity of the 32/34-kDa proteins as PF3D7_0527500 not confirmed in the source
    • activity is attributed to the HSC70/32-34-kDa complex, not to HIP individually
    • shown in P. knowlesi, not P. falciparum

Open questions

Synthesis pass · forward-looking unresolved questions
  • Whether PF3D7_0527500 physically participates in the actin-regulating HSC70 complex, and what its role is in intact parasites, remains unresolved.
  • no genetic knockout or knockdown phenotype for PF3D7_0527500 reported
  • no confirmed link between the biochemically characterized co-chaperone and the actin-capping complex

Mechanism profile

Synthesis pass · controlled-vocabulary classification
Partners
PFHSP70-1 (EEVD MOTIF HSP70) [#0]PFHSP70-2 [#0]

Evidence

Reading pass · 2 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2006 PF3D7_0527500 (PfHip, Hsp70-interacting protein) was cloned, overexpressed, and shown to enhance the chaperone activity of PfHsp70-1 (which carries the C-terminal EEVD motif) and PfHsp70-2 in an ATP-dependent manner. Binding of protein substrates to PfHip was unaffected by the antimalarial compound 15-deoxyspergualin (DSG). Cloning, overexpression, and in vitro chaperone activity assay with and without ATP and DSG Biochemical and biophysical research communications Medium 16884692
1998 A complex of HSC70 with 32/34-kDa proteins (co-purifying from F-actin affinity and ATP-agarose columns, and co-eluting by gel filtration) from Plasmodium knowlesi merozoites inhibited actin polymerization in vitro in a calcium-independent, phosphatidylinositol-4,5-bisphosphate-sensitive manner, consistent with filament-capping activity. The identity of the 32/34-kDa proteins as PF3D7_0527500 (HIP) is not explicitly stated in this abstract; the finding is attributed to the HSC70/32/34-kDa complex. F-actin affinity chromatography, ATP-agarose chromatography, gel filtration, in vitro actin polymerization assay, Western blotting, tryptic peptide microsequencing Molecular and biochemical parasitology Low 9662713

Source papers

Stage 0 corpus · 5 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
1989 Heat shock cognate 70 is a prominent immunogen in Brugian filariasis. Journal of immunology (Baltimore, Md. : 1950) 81 2659668
2001 Generation of cytotoxic T lymphocytes by MHC class I ligands fused to heat shock cognate protein 70. International immunology 70 11581168
2006 15-Deoxyspergualin modulates Plasmodium falciparum heat shock protein function. Biochemical and biophysical research communications 51 16884692
1998 Actin-binding proteins of invasive malaria parasites and the regulation of actin polymerization by a complex of 32/34-kDa proteins associated with heat shock protein 70kDa. Molecular and biochemical parasitology 33 9662713
2002 Merozoite surface protein 1-specific immune response is protective against exoerythrocytic forms of Plasmodium yoelii. Infection and immunity 26 12379684