Project SummaryMalaria parasites require pantothenate (Pan) from both the insect and mammalian hosts to synthesizecoenzyme A (CoA) and acetyl-CoA (AC). Further mosquito-stage parasites cannot take up preformed CoAfrom the insect host so they are entirely dependent on mosquito Pan availability. Thus we hypothesize thatreducing Pan stores in the mosquito by increasing Pan kinase (PanK) activity and in turn CoA biosynthesiswill limit parasite survival in the mosquito without impacting the availability of CoA/AC to the mosquito itself.PanK is the rate-limiting enzyme in the CoA biosynthesis pathway and a logical target for our approach. In thisstudy we will focus on increasing PanK activity in the mosquito to convert Pan into CoA and starve the malariaparasite of this essential precursor. To accomplish this we will utilize PanK-targeted small molecules orpantazines and genetic manipulation of PanK in our study host Anopheles stephensi. We will screenpantazines from a library of compounds developed by our collaborators at St. Jude Childrens Hospital. InAim 1 we will use a Go-No Go strategy for pantazine screening that culminates in testing the capacity ofselected pantazines to reduce P. falciparum and Plasmodium yoelii infections in A. stephensi. Aim 2 willvalidate the bioactivity and specificity of candidate pantazines identified in the screen in Aim 1. The specificityof candidate pantazines to activate PanK will be assessed through RNAi or CRISPR/Cas9 knockdown ofPanK followed by a characterization of the impact on Pan CoA AC and parasite infection success.Concurrent with Aims 1 and 2 we will generate transgenic A. stephensi with increased PanK activity anddetermine the impact on Pan levels and parasite survival in Aim 3. The generation of transgenic mosquitoeswith increased midgut PanK expression will contribute to our assessment of PanK-dependent depletion of Panstores on parasite infection as well as other aspects of mosquito biology related to vectorial capacity.Specifically we will define the effects of mosquito PanK activation via both pantazine treatment and molecularmanipulations on A. stephensi lifespan stress responses metabolism and reproduction. These studies willreveal important new insights into nutrient-driven mosquito-parasite interactions that drive parasite infectionsuccess and they will support future efforts to optimize pantazines and novel transgenic lines as distinctstrategies for mosquito-targeted malaria control.