Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
MacLachlan, I; Steyrer, E; Hermetter, A; Nimpf, J; Schneider, WJ.
Molecular characterization of quail apolipoprotein very-low-density lipoprotein II: disulphide-bond-mediated dimerization is not essential for inhibition of lipoprotein lipase.
BIOCHEM J. 1996; 317: 599-604.
Doi: 10.1042/bj3170599
[OPEN ACCESS]
Web of Science
PubMed
FullText
FullText_MUG
- Co-Autor*innen der Med Uni Graz
- Steyrer Ernst
- Altmetrics:
- Dimensions Citations:
- Plum Analytics:
- Scite (citation analytics):
- Abstract:
- As part of the avian reproductive effort, large quantities of triglyceride-rich very-low-density lipoprotein (VLDL) particles are transported by receptor-mediated endocytosis into the female germ cells. Although the oocytes are surrounded by a layer of granulosa cells harbouring high levels of active lipoprotein lipase, non-lipolysed VLDL is transported into the yolk. This is because VLDL particles from laying chickens are protected from lipolysis by apolipoprotein (apo)-VLDL-II, a potent dimeric lipoprotein lipase inhibitor [Schneider, Carroll, Severson and Nimpf (1990) J. Lipid Res. 31, 507-513]. To determine whether this protection depends on dimer formation and constitutes a general mechanism to ensure high levels of yolk triglycerides for embryonic utilization in birds, we have now molecularly characterized apo-VLDL-II in the Japanese quail, a frequently used avian species. Quail apo-VLDL-II shows 72% amino acid identity with the chicken protein, with most replacements being in the C-terminal region. Importantly, quail apo-VLDL-II lacks the single cysteine residue present eight residues from the C-terminus of chicken apo-VLDL-II, which is responsible for dimerization of the chicken lipoprotein lipase inhibitor. Nevertheless, monomeric quail and dimeric chicken apo-VLDL-II display, on a molar basis, identical inhibitory effects on lipoprotein lipase, underscoring the biological importance of their function. Furthermore secondary structure prediction of the 3'-untranslated region of the quail message supports a role for loop structures in the strictly oestrogen-dependent production of the lipoprotein lipase inhibitors. Our findings shed new light on the essential role of this small, hormonally regulated, protein in avian reproduction.
- Find related publications in this database (using NLM MeSH Indexing)
- Amino Acid Sequence -
- Animals -
- Apolipoproteins - genetics
- Base Sequence - genetics
- Chickens - genetics
- Coturnix - genetics
- DNA, Complementary - genetics
- Disulfides - genetics
- Enzyme Inhibitors - pharmacology
- Female - pharmacology
- Lipoprotein Lipase - antagonists and inhibitors
- Lipoproteins, VLDL - chemistry
- Male - chemistry
- Molecular Sequence Data - chemistry
- Oviposition - chemistry
- Ovum - growth and development
- Polymerase Chain Reaction - growth and development
- Protein Conformation - growth and development
- Sequence Analysis, DNA - growth and development
- Sequence Homology, Amino Acid - growth and development
- Species Specificity - growth and development