Ligand-induced CaMKIIα hub Trp403 flip, hub domain stacking, and modulation of kinase activity.

Autor: Narayanan D; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark., Larsen ASG; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark., Gauger SJ; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark., Adafia R; Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts, USA.; Chemistry-Biology Interface Training Program, University of Massachusetts, Amherst, Massachusetts, USA., Hammershøi RB; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark., Hamborg L; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark., Bruus-Jensen J; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark., Griem-Krey N; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark., Gee CL; HHMI, University of California, Berkeley, California, USA.; Department of Molecular and Cell Biology, University of California, Berkeley, California, USA.; California Institute for Quantitative Biosciences, University of California, Berkeley, California, USA.; Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, USA., Frølund B; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark., Stratton MM; Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts, USA., Kuriyan J; HHMI, University of California, Berkeley, California, USA.; Department of Molecular and Cell Biology, University of California, Berkeley, California, USA.; California Institute for Quantitative Biosciences, University of California, Berkeley, California, USA.; Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.; Department of Chemistry, University of California, Berkeley, California, USA.; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA., Kastrup JS; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark., Langkilde AE; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark., Wellendorph P; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark., Solbak SMØ; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
Jazyk: angličtina
Zdroj: Protein science : a publication of the Protein Society [Protein Sci] 2024 Oct; Vol. 33 (10), pp. e5152.
DOI: 10.1002/pro.5152
Abstrakt: γ-Hydroxybutyric acid (GHB) analogs are small molecules that bind competitively to a specific cavity in the oligomeric CaMKIIα hub domain. Binding affects conformation and stability of the hub domain, which may explain the neuroprotective action of some of these compounds. Here, we describe molecular details of interaction of the larger-type GHB analog 2-(6-(4-chlorophenyl)imidazo[1,2-b]pyridazine-2-yl)acetic acid (PIPA). Like smaller-type analogs, PIPA binding to the CaMKIIα hub domain promoted thermal stability. PIPA additionally modulated CaMKIIα activity under sub-maximal CaM concentrations and ultimately led to reduced substrate phosphorylation. A high-resolution X-ray crystal structure of a stabilized CaMKIIα (6x mutant) hub construct revealed details of the binding mode of PIPA, which involved outward placement of tryptophan 403 (Trp403), a central residue in a flexible loop close to the upper hub cavity. Small-angle X-ray scattering (SAXS) solution structures and mass photometry of the CaMKIIα wild-type hub domain in the presence of PIPA revealed a high degree of ordered self-association (stacks of CaMKIIα hub domains). This stacking neither occurred with the smaller compound 3-hydroxycyclopent-1-enecarboxylic acid (HOCPCA), nor when Trp403 was replaced with leucine (W403L). Additionally, CaMKIIα W403L hub was stabilized to a larger extent by PIPA compared to CaMKIIα hub wild type, indicating that loop flexibility is important for holoenzyme stability. Thus, we propose that ligand-induced outward placement of Trp403 by PIPA, which promotes an unforeseen mechanism of hub domain stacking, may be involved in the observed reduction in CaMKIIα kinase activity. Altogether, this sheds new light on allosteric regulation of CaMKIIα activity via the hub domain.
(© 2024 The Author(s). Protein Science published by Wiley Periodicals LLC on behalf of The Protein Society.)
Databáze: MEDLINE
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