secreted frizzled-related protein 3; sFRP-3; Frezzled; Fritz; FrzB-1 (FRZB FIZ FRE FRP FRZB1 SFRP3)

Function

• soluble frizzled-related proteins (sFRPS) function as modulators of Wnt signaling through direct interaction with Wnts
• they have a role in regulating cell growth & differentiation in specific cell types
• SFRP3/FRZB appears to be involved in limb skeletogenesis
• antagonist of Wnt8 signaling
• regulates chondrocyte maturation & long bone development

Structure

• the FZ domain is involved in binding with Wnt ligands
• belongs to the secreted frizzled-related protein (sFRP) family
• contains 1 FZ (frizzled) domain
• contains 1 NTR domain

Compartment

secreted (probable)

Expression

• expressed primarily in the cartilagenous cores of the long bone during embryonic & fetal development & in the appendicular skeleton (6-13 weeks)
• at 13 weeks of gestation, transcripts were present in early chondroblasts of the tarsal bones of the foot, the carpal bones of the hands & the epiphysis of long bones
• highly expressed in placenta & heart > brain, skeletal muscle, kidney & pancreas > lung & liver

Pathology

• defects in FRZB are associated with susceptibility to osteoarthritis type 1

Notes

• first purified as chondrogenic factor found in cartilage

More general terms

• secreted frizzled-related protein (sFRP) family

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=2487
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:2487
• OMIM: https://mirror.omim.org/entry/165720
• OMIM: https://mirror.omim.org/entry/605083
• UniProt: http://www.uniprot.org/uniprot/Q92765.html