Melanie J. Dobson

Professor (retired)


Phone: 902-494-7182
Mailing Address: 
5850 College Street, Room 10-J1
Sir Charles Tupper Medical Building
PO Box 15000
Halifax, Nova Scotia, Canada B3H 4R2


  • DPhil, Oxford University

Academic Positions

  • Department member since 1993
  • Undergraduate Program Advisor

Research Topics:

Yeast and Mammalian Molecular Genetics


Plasmid segregation and chromosome function

The focus of the laboratory involves NSERC-funded studies of chromosome and plasmid segregation. We are studying the inheritance of a plasmid, the 2µm circle, found at high copy number in the nucleus of most strains of the brewing yeast, Saccharomyces cerevisiae. The 2µm plasmid relies on nuclear genes for its replication and encodes proteins that allow it to borrow the host chromosome segregation machinery for its own efficient delivery to daughter cells. Our goal is to employ standard molecular genetic techniques, protein-protein and protein-DNA interaction assays and immunocytological analyses to determine how this molecular hitch-hiking occurs. Future work will include analysis of interactions of plasmid-encoded gene products with each other, with the plasmid and with other nuclear-encoded proteins including those identified as interacting specifically with the 2µm plasmid segregation locus.


yeast, molecular genetics, functional genomics, PCR, gene deletion and cloning, reporter gene assays, chromatin immunoprecipitation, Western blotting, fluorescence microscopy, protein-protein and protein-DNA interaction assays


  1. McQuaid, M.E., Mereshchuk, A., and Dobson, M.J. , (2019) Insights into the DNA sequence elements required for partitioning and copy number control of the yeast 2-micron plasmid. Current Genetics 65(4):887-892 [PubMed]
  2. McQuaid, M.E., Polvi, E.J., and Dobson, M.J. , (2019) DNA sequence elements required for partitioning competence of the Saccharomyces cerevisiae 2-micron plasmid STB locus. Nucleic Acids Research 47(2):716-728 [PubMed]
  3. McQuaid, M.E., Pinder, J.B., Arumuggam, N., Lacoste, J.S.C., Chew, J.S.K. and Dobson, M.J., (2017) The yeast 2-micron plasmid Raf protein contributes to plasmid inheritance by stabilizing the Rep1 and Rep2 partitioning proteins. Nucleic Acids Research 45(18):10518–10533 [PubMed]
  4. Caliskan, G., Baris, I.C., Ayaydin, F., Dobson, M.J., Senarisoy, M., Boros, I.M., Topcu, Z., Zencir, S. , (2017) Che1/AATF interacts with subunits of the histone acetyltransferase core module of SAGA complexes. PLoS One 12(12):e0189193 [PubMed]
  5. Pinder, J.B, McQuaid, M.E. and Dobson, M.J., (2013) Deficient sumoylation of yeast 2-micron plasmid proteins Rep1 and Rep2 associated with their loss from the plasmid-partitioning locus and impaired plasmid inheritance. PLoS One 8 (3):e60384 [PubMed]
  6. Zencir,S., Banerjee,M., Dobson.M.J., Ayaydin, F., Ayaydin Fodor, E., Topcu, Z. and Mohanty, S. , (2013) New partner proteins containing novel internal recognition motif for human Glutaminase Interacting Protein (hGIP). Biochem Biophys Res Commun. 432:10-15 [PubMed]
  7. Zencir, S., Sike, A., Dobson, M.J., Ayaydin, F., Boros, I., and Topcu, Z. , (2013) Identification of transcriptional and phosphatase regulators as interaction partners of human ADA3, a component of histone acetyltransferase complexes. Biochem. J. 450:311-320 [PubMed]
  8. Dobson, M.J., Pickett, A.J., Velmurugan, S., Pinder, J.B., Barrett, L.A., Jayaram, M., and Chew, J.S.K. , (2005) The 2µm plasmid causes cell death in yeast with a mutation in Ulp1 protease. Mol. Cell Biol. 25:4299-4310 [PubMed]
  9. Mehta, S., Yang, X.M., Chan, C.S., Dobson, M.J., Jayaram, M., and Velmurugan, S., (2002) The 2micron plasmid purloins the yeast cohesion complex: a mechanism for coupling plasmid partitioning and chromosome segregation? J. Cell Biol. 158:625-637 [PubMed]
  10. Sengupta, A., Blomqvist, K., Pickett, A., Zhang, Y., Chew, J.S.K. and Dobson, M.J., (2001) Functional domains of yeast plasmid-encoded Rep proteins. J.Bacteriol. 183:2306-2315 [PubMed]
  11. Velmurugan, S., Yang, X., Chan, C, Dobson, M.J., and Jayaram, M., (2000) Partitioning of the 2µm circle plasmid of Saccharomyces cerevisiae: functional coordination with chromosome segregation and plasmid-encoded Rep protein distribution. J. Cell Biol. 149:553-566 [PubMed]