Hai-Ying (Mary) Cheng

faculty_img Academic Title: Associate Professor

Campus: UTM

CSB Appointment: Full

Primary Undergraduate Department:
Biology, UTM

Graduate Programs:
Cell & Systems Biology
Developmental Biology

Titles and Honors:
Canada Research Chair in Molecular Genetics of Biological Clocks

Academic or Administrative Appointments:

Ph.D. University of Toronto 2003
M.Sc. University of Toronto 1999
B.Sc. University of Calgary 1996


Mailing Address
Department of Cell & Systems Biology
University of Toronto
3359 Mississauga Road
Mississauga, ON L5L 1C6


Contact Information
Office phone: 905-569-4299
Office: DV 3044
Lab: DV 4019
Lab phone: 905-569-5689
Email: haiying.cheng@utoronto.ca
URL: https://utmchenglab.wordpress.com/


Research Areas
Animal Biology
Cell Biology
Psychology & Behavior



All organisms have biological clocks, which drive and coordinate circadian rhythms in behaviour and physiology according to the demands of a 24-hour world. In mammals, the master biological clock resides in the suprachiasmatic nuclei (SCN) of the hypothalamus. The SCN has endogenous pacemaker activity that runs at near-24-hour cycles and is regulated by the environmental light cycle, thereby allowing the organism to synchronize its internal clock timing mechanism with daily and seasonal variations in the day/night cycle. While genetic studies have established that the circadian clock is comprised of a set of ‘core’ clock proteins that interact in interlocking transcription/translation feedback loops to drive rhythms in their own gene expression, our knowledge of the regulatory processes that feed into this molecular clock remains unclear. Which cascades of cellular events are needed to couple environmental light to the molecular clock? How do individual clock cells synchronize with each other to produce an ensemble rhythm in a tissue? How does aberrant regulation of the circadian clock impact on other biological clocks such as the one controlling cell division? The overall objective of our laboratory is to elucidate the cellular mechanisms that regulate biological timing in mammals, and, in turn, to understand how these cellular mechanisms manifest themselves at the “organism” scale such as animal behaviour, and play a role in diseases arising from their abnormal functioning.




Revealing a role of microRNAs in the regulation of the biological clock.Cheng HY, Obrietan K. Cell Cycle 2007 Dec;6(24):3034-5
microRNA modulation of circadian-clock period and entrainment.Cheng HY, Papp JW, Varlamova O, Dziema H, Russell B, Curfman JP, Nakazawa T, Shimizu K, Okamura H, Impey S, Obrietan K. Neuron 2007 Jun;54(5):813-29
Cannabinoids excite hypothalamic melanin-concentrating hormone but inhibit hypocretin/orexin neurons: implications for cannabinoid actions on food intake and cognitive arousal.Huang H, Acuna-Goycolea C, Li Y, Cheng HM, Obrietan K, van den Pol AN. J. Neurosci. 2007 May;27(18):4870-81


The molecular gatekeeper Dexras1 sculpts the photic responsiveness of the mammalian circadian clock.Cheng HY, Dziema H, Papp J, Mathur DP, Koletar M, Ralph MR, Penninger JM, Obrietan K. J. Neurosci. 2006 Dec;26(50):12984-95
Dexras1: shaping the responsiveness of the circadian clock.Cheng HY, Obrietan K. Semin. Cell Dev. Biol. 2006 Jun;17(3):345-51


Light stimulates MSK1 activation in the suprachiasmatic nucleus via a PACAP-ERK/MAP kinase-dependent mechanism.Butcher GQ, Lee B, Cheng HY, Obrietan K. J. Neurosci. 2005 Jun;25(22):5305-13


Dexras1 potentiates photic and suppresses nonphotic responses of the circadian clock.Cheng HY, Obrietan K, Cain SW, Lee BY, Agostino PV, Joza NA, Harrington ME, Ralph MR, Penninger JM. Neuron 2004 Sep;43(5):715-28
DREAM ablation selectively alters THC place aversion and analgesia but leaves intact the motivational and analgesic effects of morphine.Cheng HY, Laviolette SR, van der Kooy D, Penninger JM. Eur. J. Neurosci. 2004 Jun;19(11):3033-41
MKK7 couples stress signalling to G2/M cell-cycle progression and cellular senescence.Wada T, Joza N, Cheng HY, Sasaki T, Kozieradzki I, Bachmaier K, Katada T, Schreiber M, Wagner EF, Nishina H, Penninger JM. Nat. Cell Biol. 2004 Mar;6(3):215-26


Regulation of myocardial contractility and cell size by distinct PI3K-PTEN signaling pathways.Crackower MA, Oudit GY, Kozieradzki I, Sarao R, Sun H, Sasaki T, Hirsch E, Suzuki A, Shioi T, Irie-Sasaki J, Sah R, Cheng HY, Rybin VO, Lembo G, Fratta L, Oliveira-dos-Santos AJ, Benovic JL, Kahn CR, Izumo S, Steinberg SF, Wymann MP, Backx PH, Penninger JM. Cell 2002 Sep;110(6):737-49
DREAM is a critical transcriptional repressor for pain modulation.Cheng HY, Pitcher GM, Laviolette SR, Whishaw IQ, Tong KI, Kockeritz LK, Wada T, Joza NA, Crackower M, Goncalves J, Sarosi I, Woodgett JR, Oliveira-dos-Santos AJ, Ikura M, van der Kooy D, Salter MW, Penninger JM. Cell 2002 Jan;108(1):31-43


Calcium-regulated DNA binding and oligomerization of the neuronal calcium-sensing protein, calsenilin/DREAM/KChIP3.Osawa M, Tong KI, Lilliehook C, Wasco W, Buxbaum JD, Cheng HY, Penninger JM, Ikura M, Ames JB. J. Biol. Chem. 2001 Nov;276(44):41005-13
Essential role of the mitochondrial apoptosis-inducing factor in programmed cell death.Joza N, Susin SA, Daugas E, Stanford WL, Cho SK, Li CY, Sasaki T, Elia AJ, Cheng HY, Ravagnan L, Ferri KF, Zamzami N, Wakeham A, Hakem R, Yoshida H, Kong YY, Mak TW, Zúñiga-Pflücker JC, Kroemer G, Penninger JM. Nature 2001 Mar;410(6828):549-54
CD45 is a JAK phosphatase and negatively regulates cytokine receptor signalling.Irie-Sasaki J, Sasaki T, Matsumoto W, Opavsky A, Cheng M, Welstead G, Griffiths E, Krawczyk C, Richardson CD, Aitken K, Iscove N, Koretzky G, Johnson P, Liu P, Rothstein DM, Penninger JM. Nature 2001 Jan;409(6818):349-54