Title : Structure of betaglycan zona pellucida (ZP)-C domain provides insights into
ZP-mediated protein polymerization and
TGF-beta binding
Abstract :
- The zona pellucida ( ZP ) domain is a bipartite protein structural element comprised of ZP-N and ZP-C regions
- Most notable for its ability to mediate protein polymerization, many ZP proteins polymerize and assemble into long fibrils that form specialized extracellular matrices
- Other ZP proteins (namely, betaglycan and endoglin ) do not polymerize but serve as important membrane coreceptors for ligands in the transforming growth factor-β ( TGF-β) superfamily
- Here, we present the 2.0-Å resolution crystal structure of the betaglycan ZP-C region in combination with a downstream region known as the external hydrophobic patch (EHP)
- Similar to the ZP-N region , the ZP-C region also adopts an immunoglobulin-like fold, despite sharing no sequence homology and possessing different disulfide linkages
- The EHP region , which was previously thought to be external to the ZP region , is integral to the ZP-C domain and corresponds to the ZP-C G strand
- Our structure also indicates that the critical maturation cleavage of ZP proteins , a process that activates nascent ZP proteins for polymerization, occurs within the immunoglobulin domain at the FG loop
- Nonpolymerizing ZP proteins such as betaglycan and endoglin do not contain this cleavage site
- Finally, our structure suggests that the AB loop and the convex surface pocket are regions important for TGF-β ligand binding
Output (sent_index, trigger,
protein,
sugar,
site):
- 3. Other, , Other ZP, betaglycan, -
- 3. ZP, , Other ZP, betaglycan, -
- 8. Nonpolymerizing, , Nonpolymerizing ZP, betaglycan, -
- 8. ZP, , Nonpolymerizing ZP, betaglycan, -
Output(Part-Of) (sent_index,
protein,
site):
- 1. ZP, regions
- 5. ZP, region
- 6. ZP, domain
- 6. ZP, region
- 8. endoglin, site
- 8. proteins, site
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):