2llo | pdb_00002llo

Solution NMR-derived structure of calmodulin N-lobe bound with ER alpha peptide

spinqualitylabelsall models 2llo, 10 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2llo is a 2 chain structure with sequence from Xenopus laevis. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: CA Related: 2llq Gene: calm1, calm2 (Xenopus laevis) Resources: FirstGlance, OCA, RCSB, PDBsum Function [CALM_XENLA] Calmodulin mediates the control of a large number of enzymes, ion channels and other proteins by Ca(2+). Among the enzymes to be stimulated by the calmodulin-Ca(2+) complex are a number of protein kinases and phosphatases. [ESR1_HUMAN] Nuclear hormone receptor. The steroid hormones and their receptors are involved in the regulation of eukaryotic gene expression and affect cellular proliferation and differentiation in target tissues. Ligand-dependent nuclear transactivation involves either direct homodimer binding to a palindromic estrogen response element (ERE) sequence or association with other DNA-binding transcription factors, such as AP-1/c-Jun, c-Fos, ATF-2, Sp1 and Sp3, to mediate ERE-independent signaling. Ligand binding induces a conformational change allowing subsequent or combinatorial association with multiprotein coactivator complexes through LXXLL motifs of their respective components. Mutual transrepression occurs between the estrogen receptor (ER) and NF-kappa-B in a cell-type specific manner. Decreases NF-kappa-B DNA-binding activity and inhibits NF-kappa-B-mediated transcription from the IL6 promoter and displace RELA/p65 and associated coregulators from the promoter. Recruited to the NF-kappa-B response element of the CCL2 and IL8 promoters and can displace CREBBP. Present with NF-kappa-B components RELA/p65 and NFKB1/p50 on ERE sequences. Can also act synergistically with NF-kappa-B to activate transcription involving respective recruitment adjacent response elements; the function involves CREBBP. Can activate the transcriptional activity of TFF1. Also mediates membrane-initiated estrogen signaling involving various kinase cascades. Isoform 3 is involved in activation of NOS3 and endothelial nitric oxide production. Isoforms lacking one or several functional domains are thought to modulate transcriptional activity by competitive ligand or DNA binding and/or heterodimerization with the full length receptor. Isoform 3 can bind to ERE and inhibit isoform 1. Publication Abstract from PubMed The estrogen receptor alpha (ER-alpha) regulates expression of target genes implicated in development, metabolism, and breast cancer. Calcium-dependent regulation of ER-alpha is critical for activating gene expression and is controlled by calmodulin (CaM). Here, we present the NMR structures for the two lobes of CaM each bound to a localized region of ER-alpha (residues 287-305). A model of the complete CaM.ER-alpha complex was constructed by combining these two structures with additional data. The two lobes of CaM both compete for binding at the same site on ER-alpha (residues 292, 296, 299, 302, and 303), which explains why full-length CaM binds two molecules of ER-alpha in a 1:2 complex and stabilizes ER-alpha dimerization. Exposed glutamate residues in CaM (Glu(11), Glu(14), Glu(84), and Glu(87)) form salt bridges with key lysine residues in ER-alpha (Lys(299), Lys(302), and Lys(303)), which are likely to prevent ubiquitination at these sites and inhibit degradation of ER-alpha. Mutants of ER-alpha at the CaM-binding site (W292A and K299A) weaken binding to CaM, and I298E/K299D disrupts estrogen-induced transcription. CaM facilitates dimerization of ER-alpha in the absence of estrogen, and stimulation of ER-alpha by either Ca(2+) and/or estrogen may serve to regulate transcription in a combinatorial fashion. Structural basis for Ca2+-induced activation and dimerization of estrogen receptor alpha by calmodulin.,Zhang Y, Li Z, Sacks DB, Ames JB J Biol Chem. 2012 Mar 16;287(12):9336-44. Epub 2012 Jan 23. PMID:22275375 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Calmodulin

Proteopedia Page Contributors and Editors (what is this?)

OCA