Inhibitor-1 (l-1) and DARPP-32, which share sequence homology in the amino-terminal region, are endogenous regulators of protein phosphatase-1 (PP-1). l-1 is expressed in a wide variety of tissues, while DARPP-32 is highly enriched in caudate nucleus and striatum in mammalian brain. When a homologous site in each protein is phosphorylated by cAMP-dependent protein kinase, l-1 and DARPP-32 are converted to potent inhibitors of PP-1. Additional phosphorylation sites in DARPP-32 can regulate the functional state of DARPP-32. Phosphorylation at Ser-102 by casein kinase II regulates the ability of DARPP-32 to serve as a substrate for cAMP-dependent protein kinase. Phosphorylation of Ser-137 by casein kinase I inhibits the dephosphorylation of Thr-34 by the calcium/calmodulin-dependent protein phosphatase, calcineurin. Thus, a complex regulatory pathway for the control of PP-1 activity converges on a single molecule, DARPP-32, by way of multi-site phosphorylation by distinct classes of protein kinase. As described above for synapsin II, we have recently found that DARPP-32 and l-1 can serve as in vitro substrates for MAP kinase, cdc2 kinase and cdk5. We wish to identify these novel phosphorylation sites, determine the functional effects of these specific phosphorylations on phosphatase inhibition, and then prepare phospho-specific antibodies to these sites in order to study the physiological regulation of the state of phosphorylation.

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
5P41RR000862-23
Application #
5221570
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
23
Fiscal Year
1996
Total Cost
Indirect Cost
Manning, Lois R; Popowicz, Anthony M; Padovan, Julio C et al. (2017) Gel filtration of dilute human embryonic hemoglobins reveals basis for their increased oxygen binding. Anal Biochem 519:38-41
Boice, Michael; Salloum, Darin; Mourcin, Frederic et al. (2016) Loss of the HVEM Tumor Suppressor in Lymphoma and Restoration by Modified CAR-T Cells. Cell 167:405-418.e13
Chait, Brian T; Cadene, Martine; Olinares, Paul Dominic et al. (2016) Revealing Higher Order Protein Structure Using Mass Spectrometry. J Am Soc Mass Spectrom 27:952-65
Krutchinsky, Andrew N; Padovan, Júlio C; Cohen, Herbert et al. (2015) Maximizing ion transmission from atmospheric pressure into the vacuum of mass spectrometers with a novel electrospray interface. J Am Soc Mass Spectrom 26:649-58
Mast, Fred D; Rachubinski, Richard A; Aitchison, John D (2015) Signaling dynamics and peroxisomes. Curr Opin Cell Biol 35:131-6
Krutchinsky, Andrew N; Padovan, Júlio C; Cohen, Herbert et al. (2015) Optimizing electrospray interfaces using slowly diverging conical duct (ConDuct) electrodes. J Am Soc Mass Spectrom 26:659-67
Oricchio, Elisa; Papapetrou, Eirini P; Lafaille, Fabien et al. (2014) A cell engineering strategy to enhance the safety of stem cell therapies. Cell Rep 8:1677-1685
Zhong, Yu; Morris, Deanna H; Jin, Lin et al. (2014) Nrbf2 protein suppresses autophagy by modulating Atg14L protein-containing Beclin 1-Vps34 complex architecture and reducing intracellular phosphatidylinositol-3 phosphate levels. J Biol Chem 289:26021-37
Indiani, Chiara; O'Donnell, Mike (2013) A proposal: Source of single strand DNA that elicits the SOS response. Front Biosci (Landmark Ed) 18:312-23
Di Virgilio, Michela; Callen, Elsa; Yamane, Arito et al. (2013) Rif1 prevents resection of DNA breaks and promotes immunoglobulin class switching. Science 339:711-5

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