Evolutionarily distant I domains can functionally replace the essential ligand-binding domain of Plasmodium TRAP

• Published in: eLife Vol. 9
• Main Authors: Klug, Dennis, Goellner, Sarah, Kehrer, Jessica, Sattler, Julia, Strauss, Léanne, Singer, Mirko, Lu, Chafen, Springer, Timothy A, Frischknecht, Friedrich
• Format: Journal Article
• Language: English
• Published: England eLife Science Publications, Ltd 10.07.2020; eLife Sciences Publications Ltd; eLife Sciences Publications, Ltd
• Subjects: Adhesins; adhesion; Amino Acid Sequence; Animals; Anopheles - parasitology; Binding sites; Cell adhesion; Cell adhesion & migration; Cell migration; Disease transmission; Evolution, Molecular; Female; Gliding; Health aspects; Infection; integrin; Integrins; invasion; Ligands; malaria; Malaria - parasitology; Membrane proteins; Mice; Mice, Inbred C57BL; Microbiology and Infectious Disease; Mosquitoes; Motility; Parasites; Plasmodium; Plasmodium berghei; Plasmodium berghei - genetics; Plasmodium berghei - metabolism; Proteins; Protozoan Proteins - chemistry; Protozoan Proteins - genetics; Protozoan Proteins - metabolism; Salivary gland; Salivary Glands - parasitology; Scientific equipment industry; Sequence Alignment; Sporozoites - physiology; Springer, Timothy A; Toxoplasma; United States; Plasmodium berghei; invasion; infectious disease; microbiology; motility; adhesion; integrin; malaria
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.57572

Inserted (I) domains function as ligand-binding domains in adhesins that support cell adhesion and migration in many eukaryotic phyla. These adhesins include integrin αβ heterodimers in metazoans and single subunit transmembrane proteins in apicomplexans such as TRAP in and MIC2 in . Here we show that the I domain of TRAP is essential for sporozoite gliding motility, mosquito salivary gland invasion and mouse infection. Its replacement with the I domain from Toxoplasma MIC2 fully restores tissue invasion and parasite transmission, while replacement with the aX I domain from human integrins still partially restores liver infection. Mutations around the ligand binding site allowed salivary gland invasion but led to inefficient transmission to the rodent host. These results suggest that apicomplexan parasites appropriated polyspecific I domains in part for their ability to engage with multiple ligands and to provide traction for emigration into diverse organs in distant phyla.