Autor(es): Mishra Sanjay K; Jha Anupma; Steinhauser Amie L; Kokoza Vladimir A; Washabaugh Charles H; Raikhel Alexander S; Foster Woodbridge A; Traub Linton M

Resumo: In the anautogenous disease vector mosquitoes Anopheles gambiae and Aedes aegypti, egg development is nutritionally controlled. A blood meal permits further maturation of developmentally repressed previtellogenic egg chambers. This entails massive storage of extraovarian yolk precursors by the oocyte, which occurs through a burst of clathrin-mediated endocytosis. Yolk precursors are concentrated at clathrin-coated structures on the oolemma by two endocytic receptors, the vitellogenin and lipophorin receptors. Both these mosquito receptors are members of the low-density-lipoprotein-receptor superfamily that contain FxNPxY-type internalization signals. In mammals, this tyrosine-based signal is not decoded by the endocytic AP-2 adaptor complex directly. Instead, two functionally redundant phosphotyrosine-binding domain adaptors, Disabled 2 and the autosomal recessive hypercholesterolemia protein (ARH) manage the internalization of the FxNPxY sorting signal. Here, we report that a mosquito ARH-like protein, which we designate trephin, possess similar functional properties to the orthologous vertebrate proteins despite engaging AP-2 in an atypical manner, and that mRNA expression in the egg chamber is strongly upregulated shortly following a blood meal. Temporally regulated trephin transcription and translation suggests a mechanism for controlling yolk uptake when vitellogenin and lipophorin receptors are expressed and clathrin coats operate in previtellogenic ovaries.

Palavras-Chave: LDL receptor; Adaptor; Clathrin - Mediated endocytosis; Transcriptional regulation

Imprenta: Journal of Cell Science, v. 121, pt. 8, p. 1264-1274, 2008

Identificador do objeto digital: 10.1242/jcs.025833

Descritores: Aedes aegypti - Cell ; Aedes aegypti - Molecular Structure ; Aedes aegypti - Proteins ; Aedes aegypti - RT-PCR

Data de publicação: 2008