6jue
From Proteopedia
The complex of PDZ and PBM
Structural highlights
FunctionPARD3_RAT Adapter protein involved in asymmetrical cell division and cell polarization processes. Seems to play a central role in the formation of epithelial tight junctions. Association with PARD6B may prevent the interaction of PARD3 with F11R/JAM1, thereby preventing tight junction assembly. The PARD6-PARD3 complex links GTP-bound Rho small GTPases to atypical protein kinase C proteins. Required for establishment of neuronal polarity and normal axon formation in cultured hippocampal neurons (By similarity). Targets the phosphatase PTEN to cell junctions.[1] [2] Publication Abstract from PubMedThe evolutionarily conserved Par3/Par6/aPKC complex regulates the polarity establishment of diverse cell types and distinct polarity-driven functions. However, how the Par complex is concentrated beneath the membrane to initiate cell polarization remains unclear. Here we show that the Par complex exhibits cell cycle-dependent condensation in Drosophila neuroblasts, driven by liquid-liquid phase separation. The open conformation of Par3 undergoes autonomous phase separation likely due to its NTD-mediated oligomerization. Par6, via C-terminal tail binding to Par3 PDZ3, can be enriched to Par3 condensates and in return dramatically promote Par3 phase separation. aPKC can also be concentrated to the Par3N/Par6 condensates as a client. Interestingly, activated aPKC can disperse the Par3/Par6 condensates via phosphorylation of Par3. Perturbations of Par3/Par6 phase separation impair the establishment of apical-basal polarity during neuroblast asymmetric divisions and lead to defective lineage development. We propose that phase separation may be a common mechanism for localized cortical condensation of cell polarity complexes. Par complex cluster formation mediated by phase separation.,Liu Z, Yang Y, Gu A, Xu J, Mao Y, Lu H, Hu W, Lei QY, Li Z, Zhang M, Cai Y, Wen W Nat Commun. 2020 May 8;11(1):2266. doi: 10.1038/s41467-020-16135-6. PMID:32385244[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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