Reading, B.J., Hiramatsu, N., Schilling, J., Molloy, K.T., Glassbrook, N., Mizuta, H., Luo, W., Baltzegar, D.A., Williams, V.N., Todo, T., Hara, A., Sullivan, C.V. (2014) Lrp13 is a novel vertebrate lipoprotein receptor that binds vitellogenins in teleost fishes. Journal of Lipid Research. 55(11):2287-95.
Transcripts encoding a novel lipoprotein receptor, termed Lrp13, were sequenced from striped bass (Morone saxatilis) and white perch (M. americana) ovaries. Receptor proteins were purified from perch ovary membranes by protein-affinity chromatography employing an immobilized mixture of vitellogenins Aa and Ab. Reverse transcription (RT) PCR revealed lrp13 to be predominantly expressed in striped bass ovary, and in situ hybridization detected lrp13 transcripts in the ooplasm of early secondary growth oocytes. Quantitative RT-PCR confirmed peak lrp13 expression in the ovary during early secondary growth. Quantitative mass spectrometry revealed peak Lrp13 protein levels in striped bass ovary during late-vitellogenesis, and immunohistochemistry localized Lrp13 to the oolemma and zona radiata of vitellogenic oocytes. Previously unreported orthologues of lrp13 were identified in genome sequences of fishes, chicken (Gallus gallus), mouse (Mus musculus), and dog (Canis lupus familiaris). Zebrafish (Danio rerio) and Nile tilapia (Oreochromis niloticus) lrp13 loci are discrete and share genomic synteny. The Lrp13 appears to function as a vitellogenin receptor and may be an important mediator of yolk formation in fishes and other oviparous vertebrates. The presence of lrp13 orthologues in mammals suggests that this lipoprotein receptor is widely distributed amongst vertebrates where it may generally play a role in lipoprotein metabolism.