Cornifin (SPRR1) (IPR003302)

Short name: Cornifin

Overlapping homologous superfamilies


Family relationships


This entry represents Cornifin (also known as SPR1 or SPRR1), which encodes a novel class of polypeptides (small proline rich proteins) that are strongly induced during differentiation of human epidermal keratinocytes in vitro and in vivo.

The most characteristic feature of the SPRR gene family resides in the structure of the central segments of the encoded polypeptides that are built up from tandemly repeated units of either eight (SPRR1 and SPRR3) or nine (SPRR2) amino acids with the general consensus XKXPEPXX where X is any amino acid [PMID: 8325635].

Cornifin is a keratinocyte protein that first appears in the cell cytosol, but ultimately becomes cross-linked to membrane proteins by transglutaminase. All that results in the formation of an insoluble envelope beneath the plasma membrane. It may participate widely in the construction of cell envelopes in cornifying epithelia characterised by either increased thickness or a requirement for extreme flexibility [PMID: 8601731].

GO terms

Biological Process

GO:0018149 peptide cross-linking

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0005737 cytoplasm

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.