Localization of p0071-interacting proteins, plakophilin-related armadillo-repeat protein-interacting protein (PAPIN) and ERBIN, in epithelial cells

Abstract

PAPIN has six PDZ domains and interacts with p0071, a catenin-related protein. Recent studies have revealed that catenins determine the subcellular localization of some PDZ proteins. We have examined whether the localization of PAPIN is determined by p0071 in epithelial cells. PAPIN was localized not only on the lateral membrane but also on the apical membrane, where p0071 was absent. The targeting to both membranes was mediated by the middle region of PAPIN and did not require the p0071-interacting PDZ domain. In cells that came into contact, PAPIN was diffusely distributed on the plasma membrane, while p0071 was concentrated at immature cell -cell contacts. When epithelial cells were exposed to the low concentration of calcium, p0071 was internalized, whereas PAPIN remained on the plasma membrane. We also confirmed that the interaction with p0071 was not essential for the membrane targeting of ERBIN, a recently identified p0071-and ErbB2-binding protein. PAPIN, p0071, and ERBIN formed a complex in 293T cells. Furthermore, ERBIN and ErbB2 were colocalized with PAPIN on the lateral membrane. These findings suggest that PAPIN, p0071, and ERBIN come to the cell -cell contacts independently and interact with each other on the lateral membrane.

Targeting of p0071 to desmosomes and adherens junctions is mediated by different protein domains

“…Erbin seems to be able to associate with different types of junctions, adherens junctions, desmosomes and hemidesmosomes (Favre et al, 2001) and several lines of evidence support a role in appropriate organization of cytoskeletal elements and epithelial cell polarity in a rho-dependent manner. Recent data suggest that membrane association of papin and erbin does not depend on p0071 but that these proteins come to the regions of cell contact independently and interact with each other on the lateral membrane (Ohno et al, 2002).…”

Anchoring Junctions As Drug Targets: Role in Contraceptive Development

“…In terms of protein-protein interactions, p0071 has been shown to associate with desmocollin 3a , desmoplakin (Calkins et al, 2003), plakoglobin , and cadherin (Calkins et al, 2003;Hatzfeld et al, 2003). p0071 also interacts with erbin (Izawa et al, 2002;Jaulin-Bastard et al, 2002) and plakophilin-related armadillo repeat protein-interacting PDZ protein [papin (Deguchi et al, 2000;Ohno et al, 2002)], two PDZ-domain containing proteins that play roles in cell junction dynamics.…”

Tax1 enhances cancer cell proliferation via Ras–Raf–MEK–ERK signaling pathway

“…Erbin PDZ belongs to the type I motif. PDZ domain interacts with various proteins, such as ErbB2 (1,2,10), PSD-95 (3), P120 catenin (p0071 and d-catenin) (13), ARVCF (14,15), EBP0 (16), PAPIN (17), b4-integrin (18), bullous pemphigoid antigen-1 (18), c-Rel (19), APC (19), and so forth. The unique region in the LRR and PDZ associates with Smad (20).…”