scholarly journals SLC7 amino acid transporters of the yellow fever mosquito Aedes aegypti and their role in fat body TOR signaling and reproduction

2012 ◽  
Vol 58 (4) ◽  
pp. 513-522 ◽  
Author(s):  
Victoria K. Carpenter ◽  
Lisa L. Drake ◽  
Sarah E. Aguirre ◽  
David P. Price ◽  
Stacy D. Rodriguez ◽  
...  
Keyword(s):  
Amino Acid ◽  
Aedes Aegypti ◽  
Yellow Fever ◽  
Fat Body ◽  
Amino Acid Transporters ◽  
Yellow Fever Mosquito ◽  
Tor Signaling

scholarly journals AaCAT1 of the Yellow Fever Mosquito, Aedes aegypti

2011 ◽  
Vol 286 (12) ◽  
pp. 10803-10813 ◽  
Author(s):  
Immo A. Hansen ◽  
Dmitri Y. Boudko ◽  
Shin-Hong Shiao ◽  
Dmitri A. Voronov ◽  
Ella A. Meleshkevitch ◽  
...  
Keyword(s):  
Amino Acid ◽  
Aedes Aegypti ◽  
Yellow Fever ◽  
Fat Body ◽  
Yolk Protein ◽  
Yellow Fever Mosquito ◽  
Signaling System ◽  
Protein Precursor ◽  
Cationic Amino Acid ◽  
Nutrient Signaling

Insect yolk protein precursor gene expression is regulated by nutritional and endocrine signals. A surge of amino acids in the hemolymph of blood-fed female mosquitoes activates a nutrient signaling system in the fat bodies, which subsequently derepresses yolk protein precursor genes and makes them responsive to activation by steroid hormones. Orphan transporters of the SLC7 family were identified as essential upstream components of the nutrient signaling system in the fat body of fruit flies and the yellow fever mosquito, Aedes aegypti. However, the transport function of these proteins was unknown. We report expression and functional characterization of AaCAT1, cloned from the fat body of A. aegypti. Expression of AaCAT1 transcript and protein undergoes dynamic changes during postembryonic development of the mosquito. Transcript expression was especially high in the third and fourth larval stages; however, the AaCAT1 protein was detected only in pupa and adult stages. Functional expression and analysis of AaCAT1 in Xenopus oocytes revealed that it acts as a sodium-independent cationic amino acid transporter, with unique selectivity to l-histidine at neutral pH (K0.5l-His = 0.34 ± 0.07 mm, pH 7.2). Acidification to pH 6.2 dramatically increases AaCAT1-specific His+-induced current. RNAi-mediated silencing of AaCAT1 reduces egg yield of subsequent ovipositions. Our data show that AaCAT1 has notable differences in its transport mechanism when compared with related mammalian cationic amino acid transporters. It may execute histidine-specific transport and signaling in mosquito tissues.

scholarly journals The Fat Body Transcriptomes of the Yellow Fever Mosquito Aedes aegypti, Pre- and Post- Blood Meal

PLoS ONE ◽  
2011 ◽  
Vol 6 (7) ◽  
pp. e22573 ◽  
Author(s):  
David P. Price ◽  
Vijayaraj Nagarajan ◽  
Alexander Churbanov ◽  
Peter Houde ◽  
Brook Milligan ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Yellow Fever ◽  
Blood Meal ◽  
Fat Body ◽  
Yellow Fever Mosquito

scholarly journals Glutathione biosynthesis in the aging adult yellow-fever mosquito [Aedes aegypti (Louisville)]

1983 ◽  
Vol 210 (2) ◽  
pp. 289-295 ◽  
Author(s):  
G A Hazelton ◽  
C A Lang
Keyword(s):  
Amino Acid ◽  
Aedes Aegypti ◽  
Life Span ◽  
Yellow Fever ◽  
Time Course ◽  
Adult Life ◽  
Specific Inhibitor ◽  
Yellow Fever Mosquito ◽  
Essential Information ◽  
Glutathione Biosynthesis

Our previous findings [Hazelton & Lang (1978) Fed. Proc. Fed. Am. Soc. Exp. Biol. 37(6), 2378 (abstr.)] demonstrated a senescence-specific decrease in glutathione (GSH) concentration in the yellow-fever mosquito Aedes aegypti (Louisville)]. As a possible mechanism for this change, GSH biosynthesis was investigated in adult mosquitoes of different ages through the life-span. Biosynthesis was measured as the incorporation rate of [14C]glycine or [14C]cystine into glutathione. Essential information to validate the procedure was also obtained on the precursor-amino-acid pool sizes and kinetic parameters such as lag-time and time course of incorporation. Also, synthesis de novo rather than exchange was verified using buthionine sulphoximine, a specific inhibitor of GSH biosynthesis. The synthetic rates with either amino acid precursor varied throughout the adult life-span, but the patterns for both precursors were essentially identical. Biosynthesis was high in the newly emerged adult and decreased 62-70% (P less than 0.005) to a plateau during maturity. From the mature value there was a decrease of 36-41% (P less than 0.005) to a new plateau during senescence. Glutathione biosynthesis and concentration were correlated throughout maturity and senescence (r = 0.982) and thus biosynthesis was proportional to glutathione content. On this basis we concluded that impaired biosynthesis is the major and perhaps sole mechanism for the aging decrease in glutathione content.

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