| Structural highlights
Function
[DLG1_RAT] Essential multidomain scaffolding protein required for normal development (By similarity). Recruits channels, receptors and signaling molecules to discrete plasma membrane domains in polarized cells. Regulates the excitability of cardiac myocytes by modulating the functional expression of Kv4 channels. Functional regulator of Kv1.5 channel (By similarity). May play a role in adherens junction assembly, signal transduction, cell proliferation, synaptogenesis and lymphocyte activation.[1] [2] [3] [4]
Publication Abstract from PubMed
Membrane-associated guanylate kinases (MAGUKs) are a large family of scaffold proteins that play essential roles in tissue developments, cell-cell communications, cell polarity control, and cellular signal transductions. Despite extensive studies over the past two decades, the functions of the signature guanylate kinase domain (GK) of MAGUKs are poorly understood. Here we show that the GK domain of DLG1/SAP97 binds to asymmetric cell division regulatory protein LGN in a phosphorylation-dependent manner. The structure of the DLG1 SH3-GK tandem in complex with a phospho-LGN peptide reveals that the GMP-binding site of GK has evolved into a specific pSer/pThr-binding pocket. Residues both N- and C-terminal to the pSer are also critical for the specific binding of the phospho-LGN peptide to GK. We further demonstrate that the previously reported GK domain-mediated interactions of DLGs with other targets, such as GKAP/DLGAP1/SAPAP1 and SPAR, are also phosphorylation dependent. Finally, we provide evidence that other MAGUK GKs also function as phospho-peptide-binding modules. The discovery of the phosphorylation-dependent MAGUK GK/target interactions indicates that MAGUK scaffold-mediated signalling complex organizations are dynamically regulated.
Guanylate kinase domains of the MAGUK family scaffold proteins as specific phospho-protein-binding modules.,Zhu J, Shang Y, Xia C, Wang W, Wen W, Zhang M EMBO J. 2011 Nov 25. doi: 10.1038/emboj.2011.428. PMID:22117215[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Leonoudakis D, Conti LR, Radeke CM, McGuire LM, Vandenberg CA. A multiprotein trafficking complex composed of SAP97, CASK, Veli, and Mint1 is associated with inward rectifier Kir2 potassium channels. J Biol Chem. 2004 Apr 30;279(18):19051-63. Epub 2004 Feb 11. PMID:14960569 doi:http://dx.doi.org/10.1074/jbc.M400284200
- ↑ Mauceri D, Cattabeni F, Di Luca M, Gardoni F. Calcium/calmodulin-dependent protein kinase II phosphorylation drives synapse-associated protein 97 into spines. J Biol Chem. 2004 May 28;279(22):23813-21. Epub 2004 Mar 24. PMID:15044483 doi:http://dx.doi.org/10.1074/jbc.M402796200
- ↑ Nakagawa T, Futai K, Lashuel HA, Lo I, Okamoto K, Walz T, Hayashi Y, Sheng M. Quaternary structure, protein dynamics, and synaptic function of SAP97 controlled by L27 domain interactions. Neuron. 2004 Oct 28;44(3):453-67. PMID:15504326 doi:http://dx.doi.org/10.1016/j.neuron.2004.10.012
- ↑ El-Haou S, Balse E, Neyroud N, Dilanian G, Gavillet B, Abriel H, Coulombe A, Jeromin A, Hatem SN. Kv4 potassium channels form a tripartite complex with the anchoring protein SAP97 and CaMKII in cardiac myocytes. Circ Res. 2009 Mar 27;104(6):758-69. doi: 10.1161/CIRCRESAHA.108.191007. Epub, 2009 Feb 12. PMID:19213956 doi:10.1161/CIRCRESAHA.108.191007
- ↑ Zhu J, Shang Y, Xia C, Wang W, Wen W, Zhang M. Guanylate kinase domains of the MAGUK family scaffold proteins as specific phospho-protein-binding modules. EMBO J. 2011 Nov 25. doi: 10.1038/emboj.2011.428. PMID:22117215 doi:10.1038/emboj.2011.428
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