protocadherin-21; cadherin-related family member 1; photoreceptor cadherin; prCAD (CDHR1, KIAA1775, PCDH21, PRCAD)

Function

• potential Ca+2-dependent cell-adhesion protein
• may be required for the structural integrity of the outer segment of photoreceptor cells
• undergoes proteolytic cleavage; produces a soluble 95 kD N-terminal fragment & a 25 kD cell-associated C-terminal fragment

Structure

contains 6 cadherin domains

Compartment

• membrane (putative)
• localized at the junction between the inner & outer segments of rod & cone photoreceptors cells
• confined to the base of the outer segment
• localized on the edges of nascent evaginating disks on the side of the outer segment opposite the connecting cilium
• colocalized with rhodopsin between postnatal days 2 & 9 at the base of the growing outer segment region

Alternative splicing

named isoforms=2

Expression

• expressed at postnatal day 2 at the apical tip of the rod photoreceptor cells, the site of the developing outer segment

More general terms

• protocadherin (PCDH)
• glycoprotein
• receptor
• membrane protein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=92211
• OMIM: https://mirror.omim.org/entry/609502
• UniProt: http://www.uniprot.org/uniprot/Q96JP9.html