CD44 antigen (IPR001231)

Short name: CD44_antigen

Overlapping homologous superfamilies


Family relationships



CD44 is a polymorphic cell-surface glycoprotein synthesised in a variety of cells. The protein interacts with actin-based cytoskeletons, and co- localises with ERM proteins (ezrin, radixin and moesin) at actin filament- plasma membrane interaction sites. CD44 may be involved in cell migration, adhesion and differentiation in normal cells, as well as in metastasis in cancer cells. It is a receptor for extracellular materials, such as soluble or cell-bound hyaluronic acid, collagen, fibronectin and serglycin. The protein has a single membrane-spanning domain and has a heavily glycosylated extracellular domain; its cytoplasmic domain is reportedly associated with an ankyrin-like protein [PMID: 9048483].

Some of the proteins in this group are responsible for the molecular basis of the blood group antigens, surface markers on the outside of the red blood cell membrane. Most of these markers are proteins, but some are carbohydrates attached to lipids or proteins [Reid M.E., Lomas-Francis C. The Blood Group Antigen FactsBook Academic Press, London / San Diego, (1997)]. CD44 antigen (Phagocytic glycoprotein I) belongs to the Indian blood group system and is associated with In(a/b) antigen.

GO terms

Biological Process

GO:0007155 cell adhesion

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0016021 integral component of membrane

Contributing signatures

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