Plasmodium Hsp40 and human Hsp70: A potential cochaperone-chaperone complex

Area of Science:

• Malariology
• Molecular parasitology
• Protein biochemistry

Background:

• Plasmodium falciparum Hsp40 proteins are implicated in parasite virulence.
• Nineteen of 44 PfHsp40 members have a PEXEL motif, suggesting export to the host erythrocyte cytosol.
• It is hypothesized that exported PfHsp40s and host Hsp70 assist in parasite protein folding, contributing to virulence.

Purpose of the Study:

• To investigate the interaction between PEXEL-containing PfHsp40 proteins and human Hsp70 (hHsp70).
• To provide experimental evidence for the proposed role of PfHsp40s in malaria parasite virulence.

Main Methods:

• Analysis of Plasmodium falciparum Hsp40 protein family.
• Identification of PEXEL motifs in PfHsp40 proteins.
• Experimental validation of protein-protein interactions between specific PfHsp40 types and hHsp70.

Main Results:

• Established that Type II PfDNAJ proteins, which contain PEXEL motifs, specifically interact with hHsp70 (HSPA1A).
• Demonstrated a specific interaction between exported parasite proteins and host cell machinery.

Conclusions:

• The PEXEL motif-containing Type II PfDNAJ proteins directly interact with hHsp70.
• This interaction suggests a specific recognition factor within PfDNAJ dictates the choice of cognate Hsp70.
• Provides the first experimental evidence supporting the hypothesis of PfHsp40 involvement in host-parasite protein interactions and malaria pathogenesis.