title: Ser1928 phosphorylation by PKA stimulates the L-type Ca2+ channel CaV1.2 and vasoconstriction during acute hyperglycemia and diabetes.
abstract: Hypercontractility of arterial myocytes and enhanced vascular tone during diabetes are, in part, attributed to the effects of increased glucose (hyperglycemia) on L-type CaV1.2 channels. In murine arterial myocytes, kinase-dependent mechanisms mediate the increase in CaV1.2 activity in response to increased extracellular glucose. We identified a subpopulation of the CaV1.2 channel pore-forming subunit (α1C) within nanometer proximity of protein kinase A (PKA) at the sarcolemma of murine and human arterial myocytes. This arrangement depended upon scaffolding of PKA by an A-kinase anchoring protein 150 (AKAP150) in mice. Glucose-mediated increases in CaV1.2 channel activity were associated with PKA activity, leading to α1Cphosphorylation at Ser1928Compared to arteries from low-fat diet (LFD)-fed mice and nondiabetic patients, arteries from high-fat diet (HFD)-fed mice and from diabetic patients had increased Ser1928phosphorylation and CaV1.2 activity. Arterial myocytes and arteries from mice lacking AKAP150 or expressing mutant AKAP150 unable to bind PKA did not exhibit increased Ser1928phosphorylation and CaV1.2 current density in response to increased glucose or to HFD. Consistent with a functional role for Ser1928phosphorylation, arterial myocytes and arteries from knockin mice expressing a CaV1.2 with Ser1928mutated to alanine (S1928A) lacked glucose-mediated increases in CaV1.2 activity and vasoconstriction. Furthermore, the HFD-induced increases in CaV1.2 current density and myogenic tone were prevented in S1928A knockin mice. These findings reveal an essential role for α1Cphosphorylation at Ser1928in stimulating CaV1.2 channel activity and vasoconstriction by AKAP-targeted PKA upon exposure to increased glucose and in diabetes.
authors.affiliation: Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Nystoriak
authors.affiliation: Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA.
authors.forename: Madeline
authors.initials: M
authors.lastname: Nieves-Cintrón
authors.affiliation: Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Patriarchi
authors.affiliation: Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA.
authors.forename: Olivia R
authors.initials: OR
authors.lastname: Buonarati
authors.affiliation: Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA.
authors.forename: Maria Paz
authors.initials: MP
authors.lastname: Prada
authors.affiliation: Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA.
authors.forename: Stefano
authors.initials: S
authors.lastname: Morotti
authors.affiliation: Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Grandi
authors.affiliation: Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA.
authors.forename: Julia Dos Santos
authors.initials: JD
authors.lastname: Fernandes
authors.affiliation: Howard Hughes Medical Institute and Department of Pharmacology, University of Washington, Seattle, WA 98195, USA.
authors.forename: Katherine
authors.initials: K
authors.lastname: Forbush
authors.affiliation: Department of Pharmacology and Toxicology, Technical University of Munich, Munich D80802, Germany.
authors.forename: Franz
authors.initials: F
authors.lastname: Hofmann
authors.affiliation: Sasse Surgical Associates, Reno, NV 89502, USA.
authors.forename: Kent C
authors.initials: KC
authors.lastname: Sasse
authors.affiliation: Howard Hughes Medical Institute and Department of Pharmacology, University of Washington, Seattle, WA 98195, USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Scott
authors.affiliation: Department of Physiology and Cell Biology, University of Nevada, Reno, NV 89557, USA.
authors.forename: Sean M
authors.initials: SM
authors.lastname: Ward
authors.affiliation: Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA.
authors.forename: Johannes W
authors.initials: JW
authors.lastname: Hell
authors.affiliation: Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA. mfnavedo@ucdavis.edu.
authors.forename: Manuel F
authors.initials: MF
authors.lastname: Navedo
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000818:Animals; D020746:Calcium Channels, L-Type / Q000235:genetics / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000209:etiology / Q000235:genetics / Q000378:metabolism*; D059305:Diet, High-Fat / Q000009:adverse effects; D005260:Female; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D006943:Hyperglycemia / Q000235:genetics / Q000378:metabolism*; D015151:Immunoblotting; D008297:Male; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D009154:Mutation; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D010766:Phosphorylation / Q000187:drug effects; D012694:Serine / Q000235:genetics / Q000378:metabolism*; D014661:Vasoconstriction / Q000187:drug effects; D055815:Young Adult
chemical_list: D020746:Calcium Channels, L-Type; C419385:L-type calcium channel alpha(1C); D012694:Serine; D017868:Cyclic AMP-Dependent Protein Kinases; D005947:Glucose