312 Church St. SE
Minneapolis, MN 55455
The Veglia lab focuses on two critical aspects of cell regulation: cAMP-mediated cell signaling and calcium transport. These events are orchestrated by soluble and membrane-bound protein complexes. To characterize their structure, dynamics, and interactions, we utilize a multidisciplinary approach combining solution and solid-state NMR spectroscopy with other biophysical methods. Our goal is to understand how these protein complexes mediate allosteric signal transduction in cells and how pathological mutations of these proteins are linked to diseases.
Cyclic AMP (cAMP)-mediated cell signaling and calcium transport.
A primary cAMP receptor is the cAMP-dependent protein kinase A (PKA). This enzyme was the first kinase to be crystallized and has been used as the prototypical example for the AGC protein kinase family. In the inactive form, PKA adopts a homotetrameric assembly (holoenzyme) with two catalytic subunits (C subunits or PKA-C) and two regulatory subunits (R subunits). The holoenzyme is anchored to the membrane via A-kinase anchoring protein (AKAP). The classical activation mechanism involves cAMP binding to the R subunits and the release of PKA-C, which is free to phosphorylate a plethora of substrates. While several aberrant mutations have been discovered in the R subunit, in the past decades, mutations, deletions, and fusions have been found in the PRKACA gene encoding for PKA-C. These modifications are responsible for dysregulating cAMP signaling and the progression of diseases such as Cushing’s syndrome, myxomas, and fibrolamellar hepatocellular carcinomas. Our group utilizes spectroscopic and biophysical methods to understand how these mutations perturb the structural dynamics and allosteric signaling of PKA-C, resulting in dysfunctional cAMP signaling and leading to disease.
Calcium transport in the sarcoplasmic reticulum
Calcium transport is central to cardiac and skeletal muscle contractility. Its homeostatic balance is modulated by the sarcoplasmic reticulum Ca2+-ATPase (SERCA), which handles ~70% of intracellular Ca2+ regulation in humans. SERCA is an integral membrane protein whose function is regulated by an array of single-pass membrane proteins called regulins. Regulins keep this ATPase’s activity within a narrow physiological window. Dysregulation of SERCA activity degenerates into muscle disease. So far, seven regulins have been sequenced: phospholamban (PLN), sarcolipin (SLN), endoregulin (ELN), another regulin (ALN), myoregulin (MLN), dwarf open reading frame (DWORF), and sarcolamban (SCL, Drosophila m.). These regulins are single-pass membrane proteins that bind SERCA in the transmembrane domain and allosterically control SERCA’s apparent affinity for Ca2+ ions. Some regulins are post-translationally modified (e.g., phosphorylated, lipidation, acetylation, etc.). These events reverse or augment regulins’ regulatory function. In the past decade, it was found that SERCA’s regulatome has a new player, HAX-1, an intrinsically disordered protein that interacts with the other regulins to enhance their function. We aim to understand how regulins and HAX-1 interact with SERCA to augment or decrease Ca2+ transport and concomitant muscle contractility. Understanding the molecular determinant for Ca2+ transport by SERCA is critical to devise new and innovative therapy to counteract muscle disease, including heart failure.
Olivieri et al. ATP-competitive inhibitors modulate the substrate binding cooperativity of a kinase by altering its conformational entropy. Sci Adv. 2022 Jul 29;8(30):eabo0696. doi: 10.1126/sciadv.abo0696. Epub 2022 Jul 29. PMID: 35905186; PMCID: PMC9337769.
Olivieri et al. Multi-state recognition pathway of the intrinsically disordered protein kinase inhibitor by protein kinase A. Elife. 2020 Apr 27;9:e55607. doi: 10.7554/eLife.55607. PMID: 32338601; PMCID: PMC7234811.
Olivieri et al. Defective internal allosteric network imparts dysfunctional ATP/substrate-binding cooperativity in oncogenic chimera of protein kinase A. Commun Biol. 2021 Mar 10;4(1):321. doi: 10.1038/s42003-021-01819-6.
Walker et al. Cushing's syndrome driver mutation disrupts protein kinase A allosteric network, altering both regulation and substrate specificity. Sci Adv. 2019 Aug 28;5(8):eaaw9298. doi: 10.1126/sciadv.aaw9298. PMID: 31489371; PMCID: PMC6713507.
Wang et al. Globally correlated conformational entropy underlies positive and negative cooperativity in a kinase's enzymatic cycle. Nat Commun. 2019 Feb 18;10(1):799. doi: 10.1038/s41467-019-08655-7. PMID: 30778078; PMCID: PMC6379427.
Reddy et al. A kink in DWORF helical structure controls the activation of the sarcoplasmic reticulum Ca2+-ATPase. Structure. 2022 Mar 3;30(3):360-370.e6. doi: 10.1016/j.str.2021.11.003. Epub 2021 Dec 6. PMID: 34875216; PMCID: PMC8897251.
Wang et al. Structural basis for sarcolipin's regulation of muscle thermogenesis by the sarcoplasmic reticulum Ca2+-ATPase. Sci Adv. 2021 Nov 26;7(48):eabi7154. doi: 10.1126/sciadv.abi7154. Epub 2021 Nov 26. PMID: 34826239; PMCID: PMC8626070.
Weber et al. Structural basis for allosteric control of the SERCA-Phospholamban membrane complex by Ca2+ and phosphorylation. Elife. 2021 May 12;10:e66226. doi: 10.7554/eLife.66226. PMID: 33978571; PMCID: PMC8184213.
Gopinath T et al. Solid-State NMR of Membrane Proteins in Lipid Bilayers: To Spin or Not To Spin? Acc Chem Res. 2021 Mar 16;54(6):1430-1439. doi: 10.1021/acs.accounts.0c00670. Epub 2021 Mar 3. PMID: 33655754.
Larsen et al. Intrinsically disordered HAX-1 regulates Ca2+ cycling by interacting with lipid membranes and the phospholamban cytoplasmic region. Biochim Biophys Acta Biomembr. 2020 Jan 1;1862(1):183034. doi: 10.1016/j.bbamem.2019.183034. Epub 2019 Aug 7. PMID: 31400305; PMCID: PMC6899184.
M.S. in Chemistry, University of Rome ‘La Sapienza’, Rome - Italy (1991)
Ph.D. in Chemistry, University of Rome ‘La Sapienza’, Rome - Italy (1994)
Visiting Scholar, SUNY Stonybrook, NY – USA (1994)
Noopolis Postdoctoral Fellow, University of Pennsylvania, Philadelphia - USA (1995 - 2000)