The Human PDZome: A Gateway to PSD95-Disc Large-Zonula Occludens (PDZ)-mediated Functions

Abstract

Protein–protein interactions organize the localization, clustering, signal transduction, and degradation of cellular proteins and are therefore implicated in numerous biological functions. These interactions are mediated by specialized domains able to bind to modified or unmodified peptides present in binding partners. Among the most broadly distributed protein interaction domains, PSD95-disc large-zonula occludens (PDZ) domains are usually able to bind carboxy-terminal sequences of their partners. In an effort to accelerate the discovery of PDZ domain interactions, we have constructed an array displaying 96% of the human PDZ domains that is amenable to rapid two-hybrid screens in yeast. We have demonstrated that this array can efficiently identify interactions using carboxy-terminal sequences of PDZ domain binders such as the E6 oncoviral protein and protein kinases (PDGFRβ, BRSK2, PCTK1, ACVR2B, and HER4); this has been validated via mass spectrometry analysis. Taking advantage of this array, we show that PDZ domains of Scrib and SNX27 bind to the carboxy-terminal region of the planar cell polarity receptor Vangl2. We also have demonstrated the requirement of Scrib for the promigratory function of Vangl2 and described the morphogenetic function of SNX27 in the early Xenopus embryo. The resource presented here is thus adapted for the screen of PDZ interactors and, furthermore, should facilitate the understanding of PDZ-mediated functions.

The PDZ domain protein Mcc is a novel effector of non-canonical Wnt signaling during convergence and extension in zebrafish

“…In addition, the Vangl2 cytoplasmic tail contains a second, non-canonical PDZ interaction motif that involves (at least) serine 464, which is mutated to asparagine (S464N) in the classic Looptail mouse (Kibar et al, 2001). This unconventional motif facilitates the interaction between Vangl2 and the Dishevelled (Dvl) family of PDZ domain-containing proteins (Belotti et al, 2013;Torban et al, 2004). We therefore investigated whether epitope-tagged versions of Vangl2 and Mcc directly interact using pull-down assays in HEK293 cells.…”

“…The Vangl2 C-terminal tail terminates with the type I PDZ interaction motif ETSV, which has previously been shown to mediate its direct interaction with the PDZ protein Scrib (Belotti et al, 2013;Kalyoncu et al, 2010;Montcouquiol et al, 2006). In addition, the Vangl2 cytoplasmic tail contains a second, non-canonical PDZ interaction motif that involves (at least) serine 464, which is mutated to asparagine (S464N) in the classic Looptail mouse (Kibar et al, 2001).…”

The functions of tumor suppressor PTEN in innate and adaptive immunity

“…6,11,19,47 In addition, Yes-associated protein (YAP), the main downstream target of the mammalian Hippo pathway, could downregulate PTEN by inducing miR-29 to inhibit PTEN translation. As PTEN is an upstream negative regulator of mammalian target of rapamycin (mTOR), YAP can activate mTOR and can promote mTOR-mediated cell proliferation through diminishing PTEN expression.…”

“…10 PDZ-BD domains are found in numerous proteins, such as Vangl2, which normally mediate protein-protein interactions through binding to proteins containing PDZ domains. 11 The PTEN PDZ-BD (aa 384-403) domain is a functional type 1 PDZ-binding motif (PDZ-BM). 12 The C-terminal eight residues 'HTQITKVT' of PTEN are important for specific recognition of PDZ domains, and the phosphorylation of proximal residues of the PTEN C-terminal tail (Ser380/Thr382/Thr383) can diminish binding to PDZ domains, likely by maintaining the C terminus of PTEN in a closed conformation.…”

The intracellular carboxyl terminal domain of Vangl proteins contains plasma membrane targeting signals

“…11 More recently, interaction with a member of the nexin family, the PDZ containing protein SNX-27, which promotes the recycling of transmembrane proteins from endosomes to the PM has also been demonstrated. 20 Additionally, this motif was also shown to affect the localization of Vangl2 at post-synaptic sites in the rat brain, by directly mediating interaction between Vangl2 and the third PDZ motif of PSD-95. 20 These findings together with the results reported here strongly suggest that the PDZ binding motif of Vangl proteins is required for interactions with a number of PCP proteins, which is essential for targeting PCP complexes to the PM.…”