title: NMR resonance assignments of the catalytic domain of human serine/threonine phosphatase calcineurin in unligated and PVIVIT-peptide-bound states.
abstract: Calcineurin (Cn) is a serine/threonine phosphatase that plays pivotal roles in many physiological processes. In T cell, Cn targets the nuclear factors of activated T-cell (NFATs), transcription factors that activate cytokine genes. Elevated intracellular calclium concentration activates Cn to dephosphorylate multiple serine residues within the NFAT regulatory domain, which triggers joint nuclear translocation of NFAT and Cn. This relies on the interaction between the catalytic domain of Cn (CnA) and the conserved PxIxIT motif. Here, we present the assignment of CnA resonances in unligated form and in complex with a 14-residue peptide containing a PVIVIT sequence that was derived from affinity driven peptide selection based on the conserved PxIxIT motif of NFATs. Although a complete assignment was not possible mainly due to the paramagnetic line broadening induced by an iron in the CnA catalytic center, the assignment was extensively verified by amino-acid selective labeling of Arg, Leu, Lys, and Val, which cover one third of the CnA residues. Nevertheless, the assignments were used to determine the structure of the CnA-PVIVIT peptide complex and provide the basis for investigation of the interactions of CnA with physiological interaction partners and small organic compounds that disrupt the Cn-NFAT interaction.
authors.affiliation: Department of Biochemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA, 02115, USA, koh-takeuchi@aist.go.jp.
authors.forename: Koh
authors.initials: K
authors.lastname: Takeuchi
authors.forename: Zhen-Yu J
authors.initials: ZY
authors.lastname: Sun
authors.forename: Shuai
authors.initials: S
authors.lastname: Li
authors.forename: Maayan
authors.initials: M
authors.lastname: Gal
authors.forename: Gerhard
authors.initials: G
authors.lastname: Wagner
mesh_terms: D000595:Amino Acid Sequence; D019703:Calcineurin / Q000737:chemistry* / Q000378:metabolism*; D020134:Catalytic Domain; D006801:Humans; D008958:Models, Molecular; D050778:NFATC Transcription Factors / Q000737:chemistry / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding
chemical_list: D050778:NFATC Transcription Factors; D010446:Peptide Fragments; D019703:Calcineurin