Collagen XVII and BPAG1 expression in the retina: Evidence for an anchoring complex in the central nervous system

Abstract

The ectoderm gives rise not only to the skin but also to the entire CNS. This common embryonic lineage suggests that some molecular isoforms might serve analogous functions in both tissues. Indeed, not only are laminins important components of dermal adhesion mechanisms, but they also regulate some aspects of synaptic development in both the CNS and the PNS. In the skin, laminins are part of a hemidesmosome complex essential for basal keratinocyte adhesion that includes collagen XVII (BP180) and BPAG1 (dystonin/BP230). Here, we show that CNS neurons also express collagen XVII and BPAG1 and that these molecules are expressed in the adult and developing retina. In the retina, isoforms of collagen XVII and BPAG1 are colocalized with laminins at photoreceptor synapses and around photoreceptor outer segments; both molecules are expressed by rods, whereas cones express collagen XVII but not BPAG1. Moreover, biochemical data demonstrate that collagen XVII complexes with retinal laminins. We propose that collagen XVII and BPAG1 isoforms may help to anchor elements of the rod photoreceptor cytomatrix to the extracellular matrix.

Sera of Elderly Bullous Pemphigoid Patients with Associated Neurological Diseases Recognize Bullous Pemphigoid Antigens in the Human Brain

“…In the central nervous system, BPAG1 and BPAG2 are colocalized at the synaptic and extrasynaptic regions [11,12] . Both BPAG1 and BPAG2 are considered components of the neural-specific anchoring complex to which central nervous system laminins bind to stabilize presynaptic terminals to the underlying extracellular matrix.…”

“…Both BPAG1 and BPAG2 are considered components of the neural-specific anchoring complex to which central nervous system laminins bind to stabilize presynaptic terminals to the underlying extracellular matrix. This composition resembles the laminin-anchoring complex of the skin, in which BPAG1 and BPAG2 play critical roles in stabilizing the dermal-epidermal junction [11,12] . BPAG1-and BPAG2-associated defects in the lamininanchoring complex in the synapse may contribute to the neurological symptoms observed in BP+ND patients [11][12][13] .…”

Nok plays an essential role in maintaining the integrity of the outer nuclear layer in the zebrafish retina

“…Members of the cellmatrix adhesion molecules group function primarily in adhering retinal cells to the ECM, e.g. ECM components WIF-1 (Hunter et al, 2004) and laminins (Colognato and Yurchenco, 2000;Libby et al, 1999), and transmembrane proteins Collagen XVII (Claudepierre et al, 2005) and α6 integrin (Georges-labouesse et al, 1998). Members of the pan-retina cell-cell adhesion molecules group are expressed in many cell types in the retina to mediate nonspecific retinal cell adhesion.…”

Alterations in type I hemidesmosome components suggestive of epigenetic control in the salivary glands of patients with Sjögren's syndrome

“…In our system, high levels of BP230 protein may improve anchorage to the BL, thus allowing BP180 binding. As demonstrated in the retina, this adhesion complex is sufficient to preserve laminin binding (29). The SPARC protein is expressed by endometrial cancer cells and displays traits similar to those of BP230 (30).…”