Uterine Smooth Muscle S-Nitrosylproteome in Pregnancy

   1. Craig Ulrich,
   2. David R. Quillici,
   3. Kathleen Schegg,
   4. Rebekah Woolsey,
   5. Akira Nordmeier and
   6. Iain L. O. Buxton

   1.
      Department of Pharmacology, University of Nevada School of Medicine (C.U., A.N., I.L.O.B.), and Nevada Proteomics Center (D.R.Q., K.S., R.W.), University of Nevada, Reno, Nevada

   1. Address correspondence to:
      Professor Iain Buxton, Department of Pharmacology, University of Nevada School of Medicine, 1664 N. Virginia St., Reno, NV 89557. E-mail: ibuxton{at}medicine.nevada.edu

Abstract

The molecular mechanisms involved in uterine quiescence during gestation and those responsible for induction of labor are not completely known. Nitric oxide relaxes uterine smooth muscle in a manner disparate from that for other smooth muscles because global elevation of cGMP after activation of soluble guanylyl cyclase does not relax the muscle. S-Nitrosylation, the covalent addition of an nitric oxide (NO) group to a cysteine thiol is a likely mechanism to explain the ability of NO to relax myometrium. This work is the first to describe the myometrial S-nitrosylproteome in both pregnant and nonpregnant tissue states. Using the guinea pig model, we show that specific sets of proteins involved in contraction and relaxation are S-nitrosylated in laboring and nonlaboring muscle and that many of these proteins are uniquely S-nitrosylated in only one state of the tissue. In particular, we show that S-nitrosylation of the intermediate filament protein desmin is significantly increased (5.7-fold, p < 0.005) in pregnancy and that this increase cannot be attributed solely to the increase in protein expression (1.8-fold, p < 0.005) that accompanies pregnancy. Elucidation of the myometrial S-nitrosylproteome provides a list of mechanistically important proteins that can constitute the basis of hypotheses formed to explain the regulation of uterine contraction/relaxation.
Footnotes

    *

      This work was supported by the National Institutes of Health Eunice Kennedy Shriver National Institute of Child Health and Human Development [Grant R01-HD053028]; National Institutes of Health National Center for Research Resources [Grant P20-RR016464]; and a Gates Grand Challenges Grant (to I.L.O.B.).
    *

      Article, publication date, and citation information can be found at http://molpharm.aspetjournals.org.

      http://dx.doi.org/10.1124/mol.111.075804.
    *

      ABBREVIATIONS:

      USM
          uterine smooth muscle
      NO
          nitric oxide
      LY 83583
          6-anilino-5,8-quinolinedione
      NEM
          N-ethylmaleimide
      CHAPS
          3-(3-cholamidopropyl)dimethylammonio-1-propanesulfonate
      biotin-HPDP
          N-[6-(biotinamido)hexyl]-3′-(2′-pyridyldithio) propionamide
      GSNO
          S-nitroso-glutathione
      LC
          liquid chromatography
      MS/MS
          tandem mass spectrometry
      DIGE
          two-dimensional in-gel electrophoresis
      MS
          mass spectrometry
      MALDI
          matrix-assisted laser desorption ionization
      TOF/TOF
          tandem time of flight
      S/N
          signal/noise ratio
      SNO
          S-nitrosothiol
      MYLK
          myosin light chain kinase
      HSP27
          heat shock protein β-1
      IF
          intermediate filament.

    * Received September 16, 2011.
    * Accepted October 25, 2011.

    * Copyright © 2012 The American Society for Pharmacology and Experimental Therapeutics

