Dr hab. Janusz Stępiński

Division of Biophysics
Institute of Experimental Physics
University of Warsaw
Zwirki i Wigury 93, 02-089 Warsaw, Poland

Phone: +48 22 5540769

E-mail: jastep@biogeo.uw.edu.pl

Research interests

Synthesis and biochemical, biophysical and physicochemical properties of mono-, di- and oligonucleotide 5'-mRNA cap analogues.

Professional experience

  1. sugar synthesis and analysis including their 1H & 13C NMR spectroscopy
  2. peptide synthesis
  3. aminodeoxyalditol synthesis
  4. 5'-mRNA cap structure synthesis
1972 - 1978 Senior Assistant, Faculty of Chemistry, Warsaw University, Poland
1978 - 1981, 1983 - 1999 Adjunct, Faculty of Chemistry, Warsaw University, Poland
1981 - 1983 Postdoctoral Research Associate, Institute for Biomedical Research, University of Texas at Austin, TX
1999 - Assistant Professor, Department of Biophysics, Warsaw University, Poland

Selected publications (1988-2013)


    1. Smietanski M., Werner M., Purta E., Kaminska K.H., Stepinski J., Darzynkiewicz E., Nowotny M., Bujnicki J.M.: Structural analysis of human 2’-O-ribose methyltransferases involved in mRNA cap structure formation; Nat. Commun. 5 (2014), Article No: 3004 doi: 10.1038/ncomms4004.
    2. Freire E.R., Vashisht A.A., Malvezzi A.M., Zuberek J., Langousis G., Saada E.A., Nascimento J. De F., Stepinski J., Darzynkiewicz E., Hill K., De Melo Neto O.P., Wohlschlegel J.A., Sturm N.R., Campbell D.A.: eIF4F-like complexes formed by cap-binding homolog TbEIF4E5 with TbEIF4G1 or TbEIF4G2 are implicated in post-transcriptional regulation in Trypanosoma brucei; RNA 20, (2014), 1272-1286.
    3. Stepinski J., Darzynkiewicz E.: "mRNA and snRNA Cap Analogs: Synthesis and Applications” in: Chemical Biology of Nucleic Acids. Fundamentals and Clinical Applications (V.A. Erdmann, W.T .Markiewicz and J. Barciszewski Eds) Springer Heidelberg New York Dordrecht London, 2014, pages: 511-561. (rozdział w książce)
    4. Wypijewska A., Bojarska E., Lukaszewicz M., Stępiński J., Jemielity J., Davis R.E, Darzynkiewicz E.: 7-methylguanosine diphosphate (m 7GDP) is not hydrolyzed but strongly bound by decapping scavenger (DcpS) enzymes and potently inhibits their activity; Biochemistry 51 (2012) 8003-8013.
    5. Guranowski A., Wojdyła A.M., Rydzik A.M., Stępiński J., Jemielity J.: Plant nucleoside 5 '-phosphoramidate hydrolase; simple purification from yellow lupin (Lupinus luteus) seeds and properties of homogeneous enzyme; Acta Biochim. Pol. 58 (2011) 131-136.
    6. Frank F., Fabian M.R., Stępiński J., Jemielity J., Darżynkiewicz E., Sonenberg N., Nagar B.: Structural analysis of 5'-mRNA-cap interactions with the human AG02MID domain; EMBO reports 12 (2011) 415-420.
    7. Kiraga-Motoszko K., Niedźwiecka A., Modrak-Wójcik A., Stępiński J., Darżynkiewicz E., Stolarski R.: Thermodynamics of Molecular Recognition of mRNA 5 ' Cap by Yeast Eukaryotic Initiation Factor 4E; J. Physical Chem. B, 115 (2011) 8746-8754.
    8. Liu W., Jankowska-Anyszka M., Piecyk K., Dickson L., Wallace A., Niedźwiecka A., Stępiński J., Stolarski R., Darżynkiewicz E., Kieft K., Zhao R., Jones D.N.M., Davis R.E.: Structural basis for nematode eIF4E binding an m2,2,7G-Cap and its implications for translation initiation; Nucleic Acids Res. 39 (2011) 8820-8832.


    9. Benarroch D., Jankowska-Anyszka M., Stępiński J., Darżynkiewicz E., Shuman S.: Cap analog substrates reveal three clades of cap guanine-N2 methyltransferases with distinct methyl acceptor specificities; RNA 16 (2010) 211-220.
    10. Wallace A., Filbin M.E., Veo B., McFarland C., Stępiński J., Jankowska-Anyszka M., Darżynkiewicz E., Davis R.E.: The Nematode Eukaryotic Translation Initiation Factor 4E/G Complex Works with a trans-Spliced Leader Stem-Loop To Enable Efficient Translation of Trimethylguanosine-Capped RNAs; Mol. Cell. Biol. 30 (2010) 1958-1970.
    11. Wypijewska A., Bojarska E., Stępiński J., Jankowska-Anyszka M., Jemielity J., Davis R.E., Darżynkiewicz E.: Structural requirements for Caenorhabditis elegans DcpS substrates based on fluorescence and HPLC enzyme kinetic studies; FEBS J. 277 (2010) 3003-3013.
    12. Bélanger F., Stępiński J., Darżynkiewicz E., Pelletier P.: Characterization of hMTr1, a human cap1 2'O-ribose methyltransferase; J. Biol. Chem. 285 (2010) 33037-33044.
    13. Worch R., Jankowska-Anyszka M., Niedzwiecka A., Stępiński J., Mazza C., Darżynkiewicz E., Cusack S., Stolarski R.: Diverse Role of Three Tyrosines in Binding of the RNA 5' Cap to the Human Nuclear Cap Binding Complex; J. Mol. Biol. 385 (2009) 618-627.
    14. Banerjee H., B. Palenchar J.B., Łukaszewicz M., Bojarska E., Stępiński J., Jemielity J., Guranowski A., Ng S., A. Wah D.A., Darżynkiewicz E., Bellofatto V.: Identification of the HIT-45 protein from Trypanosoma brucei as an FHIT protein/dinucleoside triphosphatase: Substrate specificity studies on the recombinant and endogenous proteins; RNA 15 (2009) 1554-1564.
    15. Liu W., Zhao R., McFarland C., Kieft J., Niedźwiecka A., Jankowska-Anyszka M., Stępiński J., Darzynkiewicz E., Jones D.N.M., Davis R.E.:Structural Insights into Parasite eIF4E Binding Specificity for m7G and m2,2,7G mRNA Caps; J. Biol. Chem. 284 (2009) 31336-31349.
    16. Mittra B., Zamudio J.R., Bujnicki J.M., Stępiński J., Darzynkiewicz E., Campbell D.A., Sturm N.R.: The TbMTr1 spliced lesder RNA cap 1 2'-O-ribose methyltransferase from Trypanosoma brucei acts with substrate specificity; J. Biol. Chem. 283 (2008) 3161-3172.
    17. Zuberek J., Kubacka D., Jablonowska A., Jemielity J., Stępiński J., Sonenberg N., Darzynkiewicz E.: Weak binding affinity of human 4EHP for mRNA cap analogs; RNA 13 (2007) 691-697.
    18. Cheng G., Cohen L., Mikhli C., Jankowska-Anyszka M., Stępiński J., Darzynkiewicz E., Davis R. E.: In vivo translation and stability of trans-spliced mRNAs in nematode embryos; Mol. Biochem. Parasitology 153 (2007) 95-106.
    19. Darzynkiewicz Z.M., Bojarska E., Kowalska J., Lewdorowicz M., Jemielity J., Kalek M., Stępiński J., Davis R.E., Darzynkiewicz E.: Interaction of human decapping scavenger with 5' mRNA cap analogues: structural requirements for catalytic activity; J. Phys. Condens. Mat. 19 (2007) 285217(6pp).
    20. Stępiński J., Wojcik J., Sienkiewicz A., Niedzwiecka A.: Synthesis and NMR spectral properties of spin labelled mRNA 5' cap analogue, a new tool for biochemical studies of cap binding proteins; J. Phys. Condens. Mat. 19 (2007) 285202(10pp).
    21. Niedzwiecka A., Stępiński J., Antosiewicz J.M., Darzynkiewicz E., Stolarski R.: Biophysical approach to studies of cap-eIF4E interaction by synthetic cap analogues; Methods Enzymol. 430 (2007) 209-246.
    22. Grudzien-Nogalska E., Stępiński J., Jemielity J., Zuberek J., Stolarski R., Rhoads R.E., Darzynkiewicz E.: Synthesis of Anti-Reverse Cap Analogs (ARCAs) and Their Applications in mRNA Translation and Stability; Methods Enzymol. 431 (2007) 203-227.
    23. Blachut-Okrasinska E., Bojarska E., Stępiński J., Antosiewicz J.M.: Kinetics of binding the mRNA cap analogues to the translation initiation factor eIF4E under second-order reaction conditions; Biophysical Chem. 47 (2007) 289-297.
    24. Lewdorowicz M., Stępiński, Kierzek R., Jemielity J., Zuberek J., Yoffe Y., Shapira M., Stolarski R., Darzynkiewicz: Synthesis of Leishmania cap-4 intermediates, cap-2 and cap-3; Nucleos. Nucleot. Nucl. Acids 26 (2007) 1339-1348.
    25. Darzynkiewicz Z.M., Bojarska E., Stępiński J., Jemielity J., Jankowska-Anyszka M., Davis R.E., Darzynkiewicz E.: Affinity of dinucleotide cap analogues for human decapping scavenger (hDcpS); Nucleos. Nucleot. Nucl. Acids 26 (2007) 1349-1352.
    26. Kalek M, Jemielity J, Darzynkiewicz ZM, Bojarska E, Stępiński J, Stolarski R, Davis RE, Darzynkiewicz E: Enzymatically stable 5' mRNA cap analogs: Synthesis and binding studies with human DcpS decapping enzyme. Bioorg. Med. Chem. 14 (2006) 3223-3230.


    27. Worch R, Niedźwiecka A, Stępiński J, Mazza C, Jankowska-Anyszka M, Darzynkiewicz E, Cusack S, Stolarski R: Specificity of recognition of mRNA 5' cap by human nuclear cap-binding complex. RNA 11 (2005) 1355-1363.
    28. Kałek M, Jemielity J, Stępiński J, Stolarski R, Darżynkiewicz E: A direct method for the synthesis of nucleoside 5'-methylenebis(phosphonate)s from nucleosides. Tetrahedron Lett. 46 (2005) 2417-2421.
    29. Yoffe Y, Żuberek J, Lewdorowicz M, Zeira Z, Keasar C, Orr-Dahan I, Jankowska-Anyszka M, Stępiński J, Darżynkiewicz E, Shapira M: Cap-binding activity of an eIF4E homolog from Leishmania. RNA 10 (2004) 1764-175.
    30. Cohen LS, Mikhli C, Friedman C, Jankowska-Anyszka M, Stępiński J, Darżynkiewicz E, Davis RE: Nematode m7GpppG - and m32,2,7GpppG - RNA decapping: Activities in Ascaris embryos and characterization of C. elegans scavenger DcpS. RNA 10 (2004) 1609-1624.
    31. Grudzień E, Stępiński J, Jankowska-Anyszka M, Stolarski R, Darżynkiewicz E. Rhoads RE: Novel cap analogs for in vitro synthesis of mRNAs with high translational efficiency. RNA 10 (2004) 1479-1487.
    32. Lewdorowicz M, Yoffe Y, Żuberek J, Jemielity J, Stępiński J, Kierzek R, Stolarski R, Shapira M, Darżynkiewicz E: Chemical synthesis and binding activity of the trypanosomatid cap-4 structure. RNA 10 (2004) 1469-1478.
    33. Żuberek J, Jemielity J, Jabłonowska A, Stępiński J, Dadlez M, Stolarski R, Darżynkiewicz E: Influence of electric charge variation at residues 209 and 159 on interaction of eIF4E with the mRNA 5' terminus. Biochemistry 43 (2004) 5370-5379.
    34. Jemielity J, Fowler T, Żuberek J, Stępiński J, Lewdorowicz M, Niedźwiecka A, Stolarski R, Darżynkiewicz E, Rhoads RE: Novel 'anti-reverse' cap analogs with superior translational properties. RNA 9 (2003) 1108-1122.
    35. Zuberek J., Wyslouch-Cieszynska A., Niedzwiecka A., Dadlez M., Stępiński J., Augustyniak W., Gingras A-C., Zhang Z., Burley S.K., Sonenberg N., Stolarski R., Darżynkiewicz E.: "Phosphorylation of eIF4E attenuates its interaction with mRNA 5' cap analogs by electrostatic repulsion: Intein-mediated protein ligation strategy to obtain phosphorylated protein", RNA 9 (2003) 52-61.
    36. Stępiński J, Waddell C, Stolarski R, Darzynkiewicz E, Rhoads RE: Synthesis and properties of mRNAs containing the novel 'anti-reverse' cap analogs 7-methyl-(3'-O-methyl)GpppG and 7-methyl-(3'-deoxy)GpppG. RNA 7 (2001) 1486-1495.


    37. Cai AL, Jankowska-Anyszka M, Centers A, Chlebicka L, Stępiński J, Stolarski R, Darzynkiewicz E, Rhoads RE: Quantitative Assessment of mRNA Cap Analogs as Inhibitors of Cell-Free Translation. Biochemistry 38 (1999) 8538-8547.
    38. Lampio A, Ahola T, Darzynkiewicz E, Stępiński J, Jankowska-Anyszka M, Kaariainen L: Guanosine Nucleotide Analogs as Inhibitors of Alphavirus mRNA Capping Enzyme. Antivirial Res. 42 (1999) 35-46.
    39. Niedzwiecka-Kornas A, Przedmojski R, Balaspiri L, Wieczorek Z, Stępiński J, Jankowska M, Lönnberg H, Darzynkiewicz E, Stolarski R: Studies on Association of mRNA Cap-analogues with a Synthetic Dodecapeptide DGIEPMWEDEKN. Nucleosides & Nucleotides 18 (1999) 1105-1106.
    40. Bojarska E, Kraciuk R, Wierzchowski J, Wieczorek Z, Stępiński J, Jankowska M, Starzynska E, Guranowski A, Darzynkiewicz E: Hydrolysis of Some mRNA 5'-cap Analogs Catalyzed by The Human Fhit Protein- and Lupin ApppA Hydrolases. Nuclosides & Nucleotides 18 (1999) 1125-1126.
    41. Guranowski A, Starzynska E, Bojarska E, Stępiński J, Darzynkiewicz E: Dinucleoside 5',5"-P1,P3-triphosphate Hydrolase from Yellow Lupin (Lupinus luteus) Seeds: Purification to Homogeneity and Hydrolysis of mRNA 5'-cap Analogs. Protein Express. Purif. 8 (1996) 416-422.
    42. Jankowska M, Stępiński J, Stolarski R, Wieczorek Z, Temeriusz A, Haber D, Darzynkiewicz E: 1H NMR and Fluorescence Studies of New mRNA 5'-cap Analogues. Collect. Czech. Chem. Commun. 61 (1996) S197-S202.
    43. Joshi B, Cai AL, Keiper BD, Minich WB, Mendez R, Beach CM, Stępiński J, Stolarski R, Darzynkiewicz E, Rhoads RE: Phosphorylation of Eukaryotic Protein Synthesis Initiation Factor 4E at Ser-209. J. Biol. Chem. 270 (1995) 14597-14603.
    44. Stępiński J, Bretner M, Jankowska M, Felczak K, Stolarski R, Wieczorek Z, Cai AL, Rhoads RE, Temeriusz A, Haber D, Darzynkiewicz E: Synthesis and Properties of P1,P2-, P1,P3- and P1,P4-Dinucleoside Di-, Tri- and tetraphosphate mRNA 5'-Cap Analogues. Nucleosides & Nucleotides 14 (1995) 717-721.
    45. Chlebicka L, Wieczorek Z, Stolarski R, Stępiński J, Darzynkiewicz E, Shugar D: Synthesis and Properties of mRNA 5'-Cap Analogues with 7-Methylguanine Replaced by Benzimidazole or 3-Methylbenzimidazole. Nucleosides & Nucleotides 14 (1995) 771-775.
    46. Jankowska M, Stępiński, Stolarski R, Temeriusz A, Darzynkiewicz E: Synthesis and Properties of New NH2 and N7 Substituted GMP and GTP 5'-mRNA Cap Analogues. Collect. Czech. Chem. Commun. 58 (1993) 138-141.
    47. Stępiński J, Grabowska L, Darzynkiewicz E, Temeriusz A, Stolarski R, Tahara SM, Shugar D, Järvinen P, Lönnberg H: Synthesis, Conformation and Hydrolytic Stability of Modified mRNA 5'-Cap Structures: P1,P3-Dinucleoside Triphosphates Derived from Guanosine and Acyclic Analogues of 7-Methyl-, N2,7-Dimethyl- and N2, N2,7-Trimethyl- guanosines. Collect. Czech. Chem. Commun. 55 (1990) 117-120.
    48. Darzynkiewicz E, Stępiński J, Ekiel I, Jin Y, Haber D, Sijuwade T, Tahara SM: ß-Globin mRNAs Capped with m7G, m2,7G or m2,2,7G Differ in Intrinsic Translation Efficiency. Nucleic Acids Res. 16 (1988) 8953-8962.

Participation in research projects

Role of 5' mRNA and 5' U snRNA cap structures in regulation of gene expression

Structure and function of cap-4 in early eukaryotes - trypanosomatides; its chemical analogues as potential drug targets against Leishmania