A multigene family that interacts with the amino terminus of plasmodium MSP-1 identified using the yeast two-hybrid system.
Merozoite surface protein 1 (MSP-1) is a high-molecular-weight protein expressed on the surface of the malaria merozoite in a noncovalent complex with other protein molecules. MSP-1 undergoes a series of proteolytic processing events, but no precise biological role for the various proteolytic fragments of MSP-1 or for the additional proteins present in the complex is known. Through the use of the yeast two-hybrid system, we have isolated genes encoding proteins that interact with a region of the amino-terminal proteolytic fragment of MSP-1 from the mouse parasite Plasmodium yoelii. This analysis has led to the isolation of two sequence-related molecules, one of which is the P. yoelii homologue of MSP-7 originally described in Plasmodium falciparum. BLAST analysis of the P. falciparum database has revealed that there are six related protein molecules present in this species encoded near each other on chromosome 13. In P. falciparum, we designated these molecules MSRP-1 to -5. Analysis of the P. yoelii database indicates a similar chromosomal organization for the two genes in the mouse parasite species. The three P. falciparum sequences with the highest degree of homology to the P. yoelii sequences isolated in the two-hybrid screen have been characterized at the molecular level (MSRP-1 to -3). Expression analysis indicated that the mRNAs are expressed at various levels in the different asexual stages. Immunofluorescence studies colocalized the expression of the MSRP molecules and the amino-terminal portion of MSP-1 to the surfaces of trophozoites. In vitro binding experiments confirmed the interaction between MSRP-1, MSRP-2, and the amino-terminal region of P. falciparum MSP-1.
Mello
Kerrianne
K
Division of Molecular Parasitology, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA.
Daly
Thomas M
TM
Morrisey
Joanne
J
Vaidya
Akhil B
AB
Long
Carole A
CA
Bergman
Lawrence W
LW
D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D019992:Databases as Topic; D019084:Fluorescent Antibody Technique, Indirect; D015151:Immunoblotting; D008297:Male; D020066:Merozoite Surface Protein 1 / Q000737:chemistry* / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D005810:Multigene Family; D010957:Plasmids / Q000378:metabolism; D010967:Plasmodium yoelii / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D020798:Two-Hybrid System Techniques
D020066:Merozoite Surface Protein 1; D012333:RNA, Messenger; D011994:Recombinant Proteins