ZP2 and ZP3 cytoplasmic tails prevent premature interactions and ensure incorporation into the zona pellucida.

Abstract

The zona pellucida contains three proteins (ZP1, ZP2, ZP3), the precursors of which possess signal peptides, 'zona' domains and short (9-15 residue) cytoplasmic tails downstream of a transmembrane domain. The ectodomains of ZP2 and ZP3 are sufficient to form the insoluble zona matrix and yet each protein traffics through oocytes without oligomerization. ZP2 and ZP3 were fluorescently tagged and molecular interactions were assayed by fluorescent complementation in CHO cells and growing oocytes. ZP2 and ZP3 traffic independently, but colocalize at the plasma membrane. However, protein-protein interactions were observed only after release and incorporation of ZP2 and ZP3 into the extracellular matrix surrounding mouse oocytes. In the absence of their hydrophilic cytoplasmic tails, ZP2 and ZP3 interacted within the cell and did not participate in the zona pellucida. A heterologous GPI-anchored 'zona' domain protein fused with the cytoplasmic tails was integrated into the zona matrix. We conclude that the cytoplasmic tails are sufficient and necessary to prevent intracellular oligomerization while ensuring incorporation of processed ZP2 and ZP3 into the zona pellucida.

• Authors: Maria Jimenez-Movilla, Jurrien Dean
• Journal: Journal of cell science (J Cell Sci) Vol. 124 Issue Pt 6 Pg. 940-50 (Mar 15 2011) ISSN: 1477-9137 [Electronic] England
• PMID: 21378311 (Publication Type: Journal Article, Research Support, N.I.H., Intramural)

Chemical References

• Egg Proteins
• Membrane Glycoproteins
• Receptors, Cell Surface
• Zona Pellucida Glycoproteins
• Zp1 protein, mouse
• Zp2 protein, mouse
• Zp3 protein, mouse

Topics

• Animals
• CHO Cells
• Cell Membrane (chemistry, genetics, metabolism)
• Cricetinae
• Cricetulus
• Egg Proteins (chemistry, genetics, metabolism)
• Female
• Membrane Glycoproteins (chemistry, genetics, metabolism)
• Mice
• Oocytes (chemistry, metabolism)
• Protein Binding
• Protein Structure, Tertiary
• Protein Transport
• Receptors, Cell Surface (chemistry, genetics, metabolism)
• Zona Pellucida (chemistry, metabolism)
• Zona Pellucida Glycoproteins