Proteolytic Processing of CD44 and Its Implications in Cancer

Figure 1

Structure of CD44. (a) The CD44 gene encodes 20 exons, of which exons 6 to 15 correspond to variable exons (v1-v10). The standard isoform only contains the constant exons. (b) CD44 is composed of an extracellular domain, a stem region, a transmembrane domain, and a cytoplasmic domain. CD44 is subject to posttranslational modifications like N- or O-glycosylation and sulfation. The extracellular domain contains conserved disulfide bridges and two BX7B domains, which are essential for hyaluronic acid (HA) binding. The cytoplasmic domain contains phosphorylation sites that regulate the interaction between CD44 and the cytoskeleton through linker proteins (modified from Misra, S. et al. Frontiers in Immunology 6:201, 2015) [20].

(a)

(b)