Faculty of Medicine
Department of Biochemistry & Molecular Biology
HALIFAX, NOVA SCOTIA | CANADA B3H 4R2 | 1 (902) 494-2480

Dr. Paul Xiang-Qin Liu, Ph.D. (Cornell)


Professor

9-M1 Tupper
(902) 494-1208
Email

Research Areas

Protein Splicing and Inteins.

Our main interests are to develop intein-based protein splicing technologies for various protein applications and to understand intein's structure-function. Inteins are protein intervening sequences that can self-excise through protein splicing. Over 500 inteins have been found in various host proteins of various organisms, and there are also intein-related protein processing in human. Crystal structures of inteins revealed a conserved splicing domain of ~130 aa in size, although most inteins also have an endonuclease domain involved in the evolutionary mobility of inteins. A current focus is on split inteins that can piece together separate polypeptides through protein trans-splicing, which are useful in various forms of protein and peptide ligation. Examples of intein-based technologies include protein function control through conditional splicing, protein synthesis and modification through protein and/or peptide ligation, protein and peptide cyclization, and protein productions in certain gene therapy and in transgenic plant procedures. The possibilities of intein-based applications are limited only by one's imagination, and they can be better explored through a deeper understanding of intein structure-function.

Graduate Students


Xudong Dai PhD (visiting) Program
Senzhu Lin PhD (visiting) Program
Aditya Pandey Masters Program
Lingling Xu PhD (visiting) Program

Honours Students


Matthew Bertrand Biochemistry/Biology
Cynthia Tram Biochemistry/Microbiology

Lab Personnel


Matthew Bertrand Summer Student
Thillaga Sathemany Summer Student
Qinyan Song BIOC 3620 Student
Cynthia Tram Summer Student

Publications

  1. Volkmann G, Volkmann V, Liu X.-Q., (2012) Site-specific protein cleavage in vivo by an intein-derived protease. FEBS Lett. 586:79-84 [PubMed]
  2. Xu L, Tremblay ML, Meng Q, Liu XQ, Rainey JK., (2012) (1)H, (13)C and (15)N NMR assignments of the aciniform spidroin (AcSp1) repetitive domain of Argiope trifasciata wrapping silk. Biomol NMR Assign. 2011 Oct 12. [Epub ahead of print]: [PubMed]
  3. Theodoro, R.C., Volkmann, G., Liu, X.-Q., and Bagagli, E., (2011) PRP8 intein in Ajellomycetaceae family pathogens: sequence analysis, splicing evaluation and homing endonuclease activity. Fungal Genetics and Biology 48:80-91
  4. Qi X, Wang J, Meng Q, Liu XQ, (2011) Alternative Nucleophilic Residues in Intein Catalysis of Protein Splicing. Protein Pept. Lett. 18:1226-1232 [PubMed]
  5. Qi X, Meng Q, Liu X.-Q., (2011) Spontaneous C-cleavage of a mini-intein without its conserved N-terminal motif A. FEBS Lett. 585(15):2513-2518 [PubMed]
  6. Volkmann G, Liu X.-Q., (2011) Intein lacking conserved C-terminal motif G retains controllable N-cleavage activity. FEBS J. 278(18):3431-3446 [PubMed]
  7. Appleby-Tagoe, J.H., Thiel, I.V., Wang, Y., Wang, Y., Mootz, H.D. and Liu, X.-Q., (2011) Highly efficient and more general cis- and trans-splicing inteins through sequential directed evolution. J. Biol. Chem. 286(39):34440-34447 [PubMed]
  8. Volkmann G, Murphy P.W., Rowland E.E., Cronan J.E. Jr, Liu X.Q., Blouin C, Byers D.M., (2010) Intein-mediated cyclization of bacterial acyl carrier protein stabilizes its folded conformation but does not abolish function. J Biol Chem. 285:8605-8614 [PubMed]
  9. Appleby, J.H., Zhou, K., Volkmann, G., and Liu, X.-Q., (2009) Novel split intein for trans-splicing synthetic peptide onto C-terminus of protein. J. Biol. Chem. 284:6194-6199 [PubMed]
  10. Volkmann, G., Sun, W., and Liu, P. X.-Q., (2009) Controllable protein cleavages through intein fragment complementation. Protein Sci. 18:2393-2402 [PubMed]
  11. Volkmann, G. and Liu, P. X.-Q., (2009) Protein C-terminal labeling and biotinylation using synthetic peptide and split-intein. PLoS ONE 4(12):e8381 [PubMed]
  12. Li, J., Sun, W., Wang, B., Xiao, X. and Liu, X.-Q., (2008) Protein trans-splicing as a means for viral vector-mediated in vivo gene therapy. Human Gene Therapy 19:958-964 [PubMed]
  13. Meng, Q., Zhang Y., and Liu, X.-Q., (2007) Rare group I intron with insertion sequence element in a bacterial ribonucleotide reductase gene. J. Bacteriol. 189:2150-2154 [PubMed]
  14. Chen, L., Zhu, F., et al., (2007) The enhancing effects of the light chain on heavy chain secretion in split delivery of factor VIII gene. Mol. Therapy 15:1856-1862 [PubMed]
  15. Meng, Q. Wang, Y. Liu, P. X.-Q., (2005) An intron-encoded protein assists RNA splicing of multiple similar introns of different genes. J Biol Chem. 280:35085-35088 [PubMed]
  16. Yang, J., Meng, Q., and Liu, X.-Q., (2004) Intein harboring large tandem repeats in replicative DNA helicase of Trichodesmium erythraeum. Mol. Microbiol. 51:1185-1192 [PubMed]
  17. Sun, W. Yang, J. Liu, X.-Q., (2004) Synthetic two-piece and three-piece split inteins for protein trans-splicing. J. Biol. Chem. 279:35281-35286 [PubMed]
  18. Liu, X.-Q. and Yang, J., (2004) Prp8 intein in fungal pathogens: target for potential antifungal drugs. FEBS Lett. 572:46-50 [PubMed]
  19. Liu, X.-Q. and Yang, J., (2004) Bacterial thymidylate synthase with intein, group II intron, and distinctive ThyX motifs. J. Bacteriol. 186:6316-6319 [PubMed]
  20. Liu, X.-Q., Yang, J., and Meng, Q., (2003) Four inteins and three group II introns encoded in a bacterial ribonucleotide reductase gene. J. Biol. Chem. 278:46826-46831 [PubMed]
  21. Liu, X.-Q. and Yang, J., (2003) Split dnaE genes encoding multiple novel inteins in Trichodesmium erythraeum. J. Biol. Chem. 278:26315-26318 [PubMed]
  22. Liu, X.-Q., (2000) Protein-splicing intein: genetic mobility, origin, and evolution. Ann. Rev. Genet. 34:61-76 [PubMed]
  23. Evans, Jr., T.C., Martin, D., Lolly, R., Panne, D., Sun, L., Ghosh, I., Chen, L., Benner, J., Liu, X.-Q., Xu, M.-Q., (2000) Protein trans-splicing and cyclization by naturally split intein from the dnaE gene of Synechocystis species PCC6803. J. Biol. Chem. 275:9091-9094
  24. Wu, H., Hu, Z., and Liu, X.-Q., (1998) Protein trans-splicing by a split intein encoded in a split DnaE gene of Synechocystis sp. PCC6803. Proc. Natl. Acad. Sci. USA 95:9226-9231 [PubMed]
Last modified: 2012-05-07