Apovitellenin I (IPR008404)

Short name: Apo-VLDL-II

Overlapping homologous superfamilies


Family relationships



This family consists of several avian apovitellenin I sequences. 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 (Gallus gallus) are protected from lipolysis by apolipoprotein (apo)-VLDL-II, a potent dimeric lipoprotein lipase inhibitor [PMID: 8713091]. Apo-VLDL-II is produced in the liver and secreted into the blood stream when induced by estrogen production in female birds.

GO terms

Biological Process

GO:0006629 lipid metabolic process

Molecular Function

GO:0004857 enzyme inhibitor activity

Cellular Component

GO:0042627 chylomicron

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.