Institute for Applied Biosciences
Biology Department, College of Arts and Sciences
Characterization of Amino Acid Transport and
Signaling in the Mosquito Fat Body
(November 15, 2013) An assistant professor at New Mexico State University will receive $1.4 million over the next four years to characterize amino acid transport and signaling in the mosquito fat body through funding from the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health. Immo Hansen, of the Institute for Applied Biosciences in the College of Arts and Sciences’ Biology Department, is partnering with colleagues to study how amino acids obtained from blood proteins are transported and interact with nutrient signaling pathways inside mosquitoes and trigger egg production. Their research could lead to the development of novel insecticides to reduce the spread of mosquito-transmitted viruses, such as Dengue fever. “Mosquitos have killed more people than any other animals and all wars combined,” Hansen said. “They take up more than their own weight in blood when they bite someone.”
Hansen was recognized for his work and recent grant at an NMSU Research Rally Friday, Nov. 15. He gave an overview of his research, including an explanation of how and why mosquitos obtain blood when they feed from a person. While male mosquitos feast on nectar or sugar water, females need blood nutrients to produce eggs. They insert the proboscis, a long thin tube, into the skin. They dig back and forth, searching for a capillary while injecting their saliva. The female mosquitos feed until their abdomens are filled to capacity. During the next three days the females digest the blood proteins and use them to produce yolk for their eggs.
Hansen and his fellow researchers are proposing an insecticide that will interfere with the pathways that lead to egg production in the mosquitos’ bodies. “If you take any of those signals away, the mosquitos won’t produce eggs,” Hansen said. By eradicating the mosquito population, researchers could prevent the spread of viruses. Although there are several ways that mosquitos contract pathogens, the most common is that they bite someone who’s already infected. Next the infection spreads through the body of the mosquito until the saliva contains the pathogen. The mosquito can then transmit it when it bites someone else. “We have to interrupt the disease transmission,” Hansen said. Mosquitos typically produce one batch of eggs from each blood meal and live an average of 10 days under natural conditions. Those in the lab can live up to three months.
Through the newly acquired grant, the research team hopes to perform a structure function analysis of amino acid transporters, to study competitive inhibitors and to interpret signaling pathways with the help of a novel fat body gene knowledge. At the end of the four years, Hansen said he expects to have published his findings and to have developed new insecticide leads that challenge amino acid transporters. Although mosquitos can develop insecticide resistance, it comes at a price, and they have problems reproducing. Because of this, Hansen explained, the Insecticide Resistance Action Committee has suggested switching from one insecticide to another to delay mosquitos’ resistance. “The specific goal of this project is to study two members of a family of nutrient amino acid transporters that mosquitos utilize to move amino acids from one organ to another,” Hansen said. “An interdisciplinary approach, a combination of molecular biology, biochemistry, organic chemistry and computational biology, will be used to research how these transporters function, identify potential inhibitors, and discover the intracellular signaling networks they activate. “I’ve worked on mosquitoes for 10 years and their importance to human health is my primary motivation.”
Hansen’s collaborators include Dmitri Boudko of Rosalind Franklin University, Lawrence Hunter of the University of Colorado at Denver and fellow NMSU professor, Jeffrey Arterburn of the Chemistry and Biochemistry Department. Hansen’s grant is the largest of several ongoing NMSU grants under the NIH Support of Competitive Research program.
– Article by Isabel A. Rodriguez; photo by Darren Phillips. See more at newscenter.nmsu.edu.
Project funded through a Support of Competitive Research grant from the National Institute of Allergy and Infectious Diseases, one of the National Institutes of Health.