Florentin Nitu, Postdoctoral Associate

 

Research Interests

I am focused on a class of intracellular calcium channels, termed ryanodine receptors, or RyRs, that play a central role in controlling muscle contraction and the heart beat, more specific:

  • the role of channel accessory proteins, including Calmodulin and FKBP in channel activity regulation and structure-function correlations.
  • the molecular mechanisms of drugs and bioactive peptides that modulate RyR channels.
  • genetically encoded fluorescent tags.

Techniques: cDNA cloning, protein mutagenesis, E. coli protein expression, recombinant protein purification, HPLC, FPLC, site-directed fluorescent labeling, fluorescence spectroscopy, CD, MS, protein analytical chemistry.

Publications

  1. Ablorh NA, Miller T, Nitu F., Gruber SJ, Karim C, Thomas DD. Accurate quantitation of phospholamban phosphorylation by immunoblot. Anal Biochem., 2012, 425(1):68-75.
  2. Guo T., Fruen B.R., Nitu F.R., Nguyen T.D., Yang Y., Cornea R.L., Bers D.M. FRET Detection of Calmodulin Binding to the Cardiac RyR2 Calcium Release Channel, Biophys. J., 2011, 101(9):2170-7.
  3. Cornea R.L., Nitu F.R., Sams M., Thomas D.D., Fruen B.R. Mapping the ryanodine receptor FK506-binding protein subunit using fluorescence resonance energy transfer. J. Biol. Chem., 2010, Jun 18; 285(25):19219-26.
  4. Ablorh NA, Nitu F., Engebretsen K, Thomas DD, Holger JS. Insulin-dependent rescue from cardiogenic shock is not mediated by phospholamban phosphorylation. Clin. Toxicol. (Phila). 2009 Apr; 47(4):296-302.
  5. Cornea R.L., Nitu F., Gruber S., Kohler K., Satzer M., Thomas D.D., Fruen B.R. FRET-based mapping of calmodulin bound to the RyR1 Ca2+ release channel. Proc. Natl. Acad. Sci. U S A, 2009, Apr 14; 106(15):6128-33.
  6. Zamoon J., Nitu F., Karim C., Thomas D.D., Veglia G. Mapping the interaction surface of a membrane protein: unveiling the conformational switch of phospholamban in calcium pump regulation. Proc. Natl. Acad. Sci. U S A, 2005 Mar 29; 102(13):4747-52.
  7. Fruen B.R., Balog E.M., Schafer J., Nitu F.R., Thomas D.D., Cornea R.L. Direct detection 7/8/2011of calmodulin tuning by ryanodine receptor channel targets using a Ca2+-sensitive acrylodan-labeled calmodulin. Biochemistry, 2005, Jan 11; 44(1):278-84.

Abstracts and Posters

  • Florentin R. Nitu, Razvan L. Cornea, David D. Thomas, Bradley R. Fruen. University of Minnesota, Minneapolis, MN, USA.Direct detection of domain peptide binding to the cardiac ryanodine receptor (RYR2) using FRET. Biophysical Society 55th Annual Meeting, March 5-9, 2011, Baltimore, Maryland, USA.
  • Bradley R. Fruen, Mallory Turner, Florentin R. Nitu, David D. Thomas, Razvan L. Cornea. University of Minnesota, Minneapolis, MN, USA. FRET detection of Calmodulin binding and structural rearrangements within the cardiac RyR2 calcium release channel (1567-Pos). Biophysical Society 54th Annual Meeting, February 20 - 24, 2010, San Francisco, California, USA.
  • Razvan L. Cornea, Florentin R. Nitu, David D. Thomas, Bradley R. Fruen. University of Minnesota, Minneapolis, MN, USA.Time-Resolved FRET detection of structural distributions involving FKBP12.6 and Calmodulin bound within macromolecular RyR channels (1558-Pos). Biophysical Society 54th Annual Meeting, February 20 - 24, 2010, San Francisco, California, USA.
  • Razvan L. Cornea, Florentin Nitu, Katherine Kohler, David D. Thomas, Bradley R. Fruen. Structural Characterization of FKBP Interactions with RyR Channels Using Site-Directed Fluorescent Labeling and FRET. Biophysical Society 53th Annual Meeting, February 28 - March 4, 2009, Boston, Massachusetts, USA.
  • Bradley Fruen, Florentin Nitu, David Th omas, Razvan Cornea. FRET-based mapping of calmodulin bound to ryanodine receptor channels. Calmodulin Modulation of Ion Channels Asilomar Conference Center, October 30 - November 2, 2008, Asilomar, California, USA.
  • Engebretsen KM, Holger JS, Harris CR, Ablorh N, Nitu F, Thomas D. Therapeutic Misadventure of High Dose Insulin without Adverse Effects. Clinical Toxicology 2008; 46(7):604. Presented at North American Congress of Clinical Toxicology, Toronto, Ontario, CA, September 2008. 
  • Razvan L. Cornea, Florentin R. Nitu, Michael B. Satzer, David D. Thomas, Bradley R. Fruen. University of Minnesota, Minneapolis, MN, USA. Fluorescent probe of FKBP interactions with ryanodine receptor channels, Biophysical Society 51th Annual Meeting, March 3-7, 2007, Baltimore, Maryland, USA.
  • Bradley R. Fruen1, E.M. Balog1, Ruiwu Wang2, S.R.W. Chen2, F. Nitu1, R.L. Cornea1. 1University of Minnesota, Minneapolis, MN, USA, 2University of Calgary, Calgary, AB, Canada. Calmodulin regulation of the type 3 ryanodine receptor , Biophysical Society 49th Annual Meeting, Presentation Session: (421-Pos/B260) , February 12-16, 2005, Long Beach, California, USA.