Abnormal dermoepidermal junction morphology Abnormal dermoepidermal hemidesmosome morphology 2019-03-03T18:24:45Z An abnormal structure or appearance of hemidesmosomes, multiprotein complexes that facilitate the stable adhesion of basal epithelial cells to the underlying basement membrane. Hemidesmosomes (HDs) are highly specialized integrin-mediated epithelial attachment structures that make cells firmly adhere to the extracellular matrix by establishing a link between the underlying basement membrane (BM) and the internal mechanical stress-resilient keratin intermediate filament (IF) network. Although HDs are defined by their ultrastructural appearance, two types of HDs, type I and II, can be distinguished on the basis of their protein components. Classical type I HDs, found in stratified and pseudostratified epithelia, for example in the epidermis, consist in five major components, namely integrin alpha6beta4, plectin isoform 1a (P1a), tetraspanin CD151, bullous pemphigoid antigen (BPAG)1 isoform e (BPAG1e, also called BP230) and BPAG2 (also called BP180 or type XVII collagen). Type II HDs, found in simple epithelia such as that of the intestine, consist of integrin alpha6beta4 and plectin and lack the two BP antigens.