In 2014, Dr Wang came to NUS to pursue his post-graduate doctoral studies under the supervision of Professor Shen Han-Ming and Associate Professor Celestial Yap. He submitted his dissertation in August 2018 and graduated from his PhD programme in December 2018. His research interest is in mitophagy. Currently, he is a postdoctoral fellow supported under the Ministry of Education Postdoctoral Fellowship Award 2018 in Professor Shen Han-Ming’s laboratory.
In 2019, he received the Yong Loo Lin School of Medicine Best Graduate Research Publication Award. His paper “PTEN-L is a novel protein phosphatase for ubiquitin dephosphorylation to inhibit PINK1-Parkin-mediated mitophagy” was published in Cell Research.
His scientific findings and achievements
Mitophagy is a selective form of autophagy in which damaged mitochondria are selectively degraded. Pphosphatase and tensin homolog (PTEN)-long (PTEN-L) is a newly identified isoform of PTEN and its biological functions remain poor studied. In this project, Liming discovered that PTEN-L is a novel negative regulator of mitophagy via its protein phosphatase activity. PTEN-L reduces the level of phosphorylated ubiquitin (pSer65-Ub) which leads to a series of events, including blockage of Parkin’s mitochondrial translocation, reduction of pSer65-Parkin level and suppression of Parkin’s E3 ligase activity. Consequently, mitophagy is inhibited.
When Liming started on his research, there were no precedent studies of PTEN-L in mitophagy and few members in the laboratory were working on projects related to mitophagy. Hence, he had to set up many new methods for this project on mitophagy, including obtain new cell lines and plasmids from the collaborators and establish new cell models with stable knockout or overexpression. More importantly, this work was made possibly via close collaboration with scientists across the world, including Prof Sze Siu Kwan from Nanyang Technological University and Prof Fang Lei from Nanjing University on mass spectrometry; Associate Prof Lim Kah Leong, Professor Bay Boon Huat and Dr Karthik Mallilankaraman from National University of Singapore. Without this network of experts, it would have been an uphill task to complete this research.
Professor Shen is very responsible and caring towards his students and laboratory members. He always avails himself for scientific discussions via weekly lab meeting and monthly individual meetings. Professor Shen not only plays the role as an academic supervisor, he also provides personal guidance and advice beyond study and science.
Equally caring and nurturing, Associate Professor Yap gave many suggestions to Liming on how to write a good and captivating academic story.
Liming would like to express his gratitude and appreciation to both his mentors for their continuous support and guidance throughout his 4 years of PhD studies.
His next step
This project has kick-started the molecular puzzle controlling mitophagy by identifying PTEN-L as a novel protein phosphatase to negatively regulate mitophagy. Moving forward, Liming and the team will be actively studying the implications of PTEN-L in human diseases such as Parkinson’s Disease.