ZP4

Zona pellucida sperm-binding protein 4 is a is_associated_with::protein that in humans is encoded by the ZP4 is_associated_with::gene.

Function
The is_associated_with::zona pellucida is an is_associated_with::extracellular matrix that surrounds the is_associated_with::oocyte and early is_associated_with::embryo. It is composed primarily of three or four is_associated_with::glycoproteins with various functions during fertilization and preimplantation development. The nascent protein contains a N-terminal is_associated_with::signal peptide sequence, a conserved is_associated_with::zona pellucida-like domain, a consensus is_associated_with::furin cleavage site, and a C-terminal transmembrane domain. It is hypothesized that furin cleavage results in release of the mature protein from the plasma membrane for subsequent incorporation into the zona pellucida matrix. However, the requirement for furin cleavage in this process remains controversial based on mouse studies.

Previously, this gene has been referred to as ZP1 or ZPB and thought to have similar functions as mouse Zp1. However, a human gene with higher similarity and chromosomal synteny to mouse Zp1 has been assigned the symbol ZP1 and this gene has been assigned the symbol ZP4.