|Raikhel, Alexander - UNIVERSITY OF CALIFORNIA|
Submitted to: Reproductive Biology of Invertebrates
Publication Type: Book / Chapter
Publication Acceptance Date: April 29, 2003
Publication Date: June 1, 2004
Citation: Sappington, T.W., Raikhel, A.S. 2004. Insect vitellogenin/yolk protein receptors. In: Raikhel, A.S., editor. Reproductive Biology of Invertebrates. Vol. 12, Part B: Progress in Vitellogenesis. Enfield, USA/Plymouth, UK: Science Publishers, Inc. p. 229-264. Technical Abstract: Growth of insect eggs is mediated by oocyte-surface receptors that specifically recognize, bind, and internalize yolk protein precursors (YPP's) from the hemolymph. The most common YPP is vitellogenin (Vg), but higher Diptera like Drosophila internalize a yolk polypeptide called YP, which is homologous to minor YPP's in Lepidoptera. Some insects also internalize lipophorin (Lp), a protein that serves as a lipid carrier. Insect Vg, YP, and Lp receptors are all members of the low-density lipoprotein receptor (LDLR) superfamily of receptors, which are widespread among animals and important in human cholesterol homeostasis. Like other LDLR-type receptors, insect YPP receptors are mosaic proteins made up of modules that have been shuffled during evolution. Because of their importance in human health, LDLR-type receptors have received a great deal of experimental attention, and much of this literature is relevant to understanding insect YPP receptor structure and function. We review what is known about the molecular and tertiary structures of the component modules, and their implications for function and binding interactions in insect YPP receptors.