Saglin and TRAP bind to enable Plasmodium infection of mosquitos’ salivary gland, according to PLoS Pathogens article.
Researchers at the Johns Hopkins Malaria Research Institute identified the molecular components that enable Plasmodium to infect the salivary glands of the Anopheles mosquito, a critical step in the spread of malaria to humans.
Investigators say saglin, a mosquito salivary protein, is a receptor for the Plasmodium protein thrombospondin-related anonymous protein (TRAP). The two proteins combine to allow invasion of the salivary gland by Plasmodium sporozoites, which can be transmitted to a human when bitten by an infected mosquito.
Through a series of experiments, the team found that saglin bound with the artificial peptide SM1. The group then developed an antibody to find a protein similar to SM1 that existed naturally in the parasite, which they identified as TRAP. To further prove the interaction between saglin and TRAP, the team conducted experiments to switch off saglin expression, which greatly diminished salivary gland invasion in the mosquito.
“This work is the culmination of a decade-long research project in which peptide libraries were used to understand the mechanisms that the parasite uses to develop in its obligatory mosquito host,” explains Marcelo Jacobs-Lorena, Ph.D., professor of genetics. “We are learning more and more about how the malaria parasite develops inside the mosquito, which could lead to novel approaches for disrupting its lifecycle and preventing the spread of malaria.”
The findings are published January 16 in PLoS Pathogens.