Structural highlights
Function
[LIN7B_MOUSE] Plays a role in establishing and maintaining the asymmetric distribution of channels and receptors at the plasma membrane of polarized cells. Forms membrane-associated multiprotein complexes that may regulate delivery and recycling of proteins to the correct membrane domains. The tripartite complex composed of LIN7 (LIN7A, LIN7B or LIN7C), CASK and APBA1 may have the potential to couple synaptic vesicle exocytosis to cell adhesion in brain. Ensures the proper localization of GRIN2B (subunit 2B of the NMDA receptor) to neuronal postsynaptic density and may function in localizing synaptic vesicles at synapses where it is recruited by beta-catenin and cadherin. Required to localize Kir2 channels, GABA transporter (SLC6A12) and EGFR/ERBB1, ERBB2, ERBB3 and ERBB4 to the basolateral membrane of epithelial cells. May increase the amplitude of ASIC3 acid-evoked currents by stabilizing the channel at the cell surface.[1] [CSKP_MOUSE] Multidomain scaffolding protein with a role in synaptic transmembrane protein anchoring and ion channel trafficking. Contributes to neural development and regulation of gene expression via interaction with the transcription factor TRB1. Binds to cell-surface proteins, including amyloid precursor protein, neurexins, and syndecans. May mediate a link between the extracellular matrix and the actin cytoskeleton via its interaction with syndecan and with the actin/spectrin-binding protein 4.1.[2]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Initially identified in Caenorhabditis elegans Lin-2 and Lin-7, L27 domain is a protein-protein interaction domain capable of organizing scaffold proteins into supramolecular assemblies by formation of heteromeric L27 domain complexes. L27 domain-mediated protein assemblies have been shown to play essential roles in cellular processes including asymmetric cell division, establishment and maintenance of cell polarity, and clustering of receptors and ion channels. The structural basis of L27 domain heteromeric complex assembly is controversial. We determined the high-resolution solution structure of the prototype L27 domain complex formed by mLin-2 and mLin-7 as well as the solution structure of the L27 domain complex formed by Patj and Pals1. The structures suggest that a tetrameric structure composed of two units of heterodimer is a general assembly mode for cognate pairs of L27 domains. Structural analysis of the L27 domain complex structures further showed that the central four-helix bundles mediating tetramer assembly are highly distinct between different pairs of L27 domain complexes. Biochemical studies revealed that the C-terminal alpha-helix responsible for the formation of the central helix bundle is a critical specificity determinant for each L27 domain in choosing its binding partner. Our results provide a unified picture for L27 domain-mediated protein-protein interactions.
A unified assembly mode revealed by the structures of tetrameric L27 domain complexes formed by mLin-2/mLin-7 and Patj/Pals1 scaffold proteins.,Feng W, Long JF, Zhang M Proc Natl Acad Sci U S A. 2005 May 10;102(19):6861-6. Epub 2005 Apr 29. PMID:15863617[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Hruska-Hageman AM, Benson CJ, Leonard AS, Price MP, Welsh MJ. PSD-95 and Lin-7b interact with acid-sensing ion channel-3 and have opposite effects on H+- gated current. J Biol Chem. 2004 Nov 5;279(45):46962-8. Epub 2004 Aug 17. PMID:15317815 doi:10.1074/jbc.M405874200
- ↑ Hsueh YP, Wang TF, Yang FC, Sheng M. Nuclear translocation and transcription regulation by the membrane-associated guanylate kinase CASK/LIN-2. Nature. 2000 Mar 16;404(6775):298-302. PMID:10749215 doi:http://dx.doi.org/10.1038/35005118
- ↑ Feng W, Long JF, Zhang M. A unified assembly mode revealed by the structures of tetrameric L27 domain complexes formed by mLin-2/mLin-7 and Patj/Pals1 scaffold proteins. Proc Natl Acad Sci U S A. 2005 May 10;102(19):6861-6. Epub 2005 Apr 29. PMID:15863617
