Miratul Muqit's Research Group

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PINK1 kinase signalling networks in Parkinson's disease

Parkinson’s disease is a progressive disorder of movement and coordination due to the specific loss of dopaminergic neurons in the brain. There are no medicines that can slow or halt the disease process largely due to lack of understanding of the fundamental mechanisms. Spectacular advances in genetics have identified 13 genes that are mutated in familial forms of the disease and nearly 90 gene variants that increase susceptibility to sporadic disease. Understanding the regulation and signaling networks in which these genes reside is likely to elaborate new knowledge on the key cellular pathways that are vital for maintaining neuronal integrity and health [1]. It may also lead to the development of novel approaches to better diagnose and treat Parkinson’s.

My lab studies the protein kinase, PTEN-induced kinase 1 (PINK1) in which loss of function mutations cause Parkinson’s disease. We are interested in understanding how PINK1 is regulated and how mutations leads to neurodegeneration. Studies to date indicate that PINK1 is a master regulator of a mitochondrial damage response pathway that exists in many different cell types including neurons. Under healthy conditions PINK1 is inactive however, upon selective mitochondrial stress, PINK1 is activated and stimulates the removal of damaged mitochondrial via autophagy (termed mitophagy) thereby promoting cell survival.

My lab found that PINK1 phosphorylates ubiquitin and Parkin at a Ser residue (Serine 65) located within a conserved fold of ubiquitin and the ubiquitin-like domain of Parkin. We also determined the mechanism of activation of Parkin E3 ligase activity by phosphorylated-ubiquitin [2]. We were able to demonstrate the relevance of our findings to the pathogenesis of Parkinson’s through analysis of a Parkin Ser65Ala knockin mouse and the discovery of rare Parkinson’s patients harbouring mutations of the Parkin Ser65 site [3]. In collaboration with the van Aalten lab we solved the first crystal structure of PINK1 using an insect orthologue that has revealed the mechanisms of how disease mutations impact on PINK1 activity [4]. Collectively our work has stimulated interest amongst industry to develop small molecule activators of Parkin and PINK1.

We have also found that PINK1 stimulates the phosphorylation of a subset of Rab GTPases (Rab1B, 8A, 8B and 13) at a conserved Ser residue (Ser111) that lies within the SF3 motif [5]. PINK1 dependent phosphorylation of Rabs disrupts its ability to interact with its cognate guanine exchange factor, Rabin8, and more recently we have found that phosphorylation impairs the ability of another Parkinson’s associated kinase LRRK2 to phosphorylate Thr72 within the Switch II domain [6].

Outstanding questions include understanding how PINK1 is activated upon mitochondrial depolarisation and determining novel regulatory proteins required for PINK1 activation. We are establishing robust methods to study PINK1 signalling in neurons and defining the downstream biology in these cell types. We are also investigating the mechanisms by which Rab GTPases are regulated by PINK1 activation.

PINK1 kinase signalling networks in Parkinson's disease
PINK1 kinase signalling networks in Parkinson's disease
Recent MM lab group meeting 2021
Recent MM lab group meeting 2021

How we do research is extremely important for the lab and we believe that diversity, inclusivity and openness are essential to create a happy and productive lab environment. We also support lab members through mentorship and personal development programmes. We want to train scientists at the highest level but who also feel valued and fulfilled in their pursuit of the next important questions in science. These together with a strong ethos in open science and public engagement will lead to the next breakthroughs in our understanding of Parkinson’s and neurodegeneration. Informal enquires on more of what we do and how we do it can be made by emailing Miratul Muqit (m.muqit@dundee.ac.uk).

People

Yinchen Chen | PhD Student
Shalini Agarwal | Postdoctoral Researcher
Odetta Antico | PhD Student
Enrico Bagnoli | Postdoctoral Researcher
Andrew Keenlyside | Summer Student
Hina Ojha | Postdoctoral Researcher
Olawale Raimi | Postdoctoral Researcher
Lucy Richardson | PhD Student
Rosamund Shastry | Postdoctoral Researcher

Selected Publications

  • Kakade P, Ojha H, Raimi OG, Shaw A, Waddell AD, Ault JR, Burel S, Brockmann K, Kumar A, Ahangar MS, Krysztofinska EM, Macartney T, Bayliss R, Fitzgerald JC, Muqit MMK (2022) Mapping of a N-terminal α-helix domain required for human PINK1 stabilization, Serine228 autophosphorylation and activation in cells Open Biology 12 1-16 doi:10.1098/rsob.210264 PMID: 35042401
  • Antico, O., Ordureau, A., Stevens, M., Singh, F., Nirujogi, R. S., Gierlinski, M., Barini, E., Rickwood, M. L., Prescott, A., Toth, R., Ganley, I. G., Harper, J. W., & Muqit, M. M. K. (2021) Global ubiquitylation analysis of mitochondria in primary neurons identifies endogenous Parkin targets following activation of PINK1 Science Advances 7 1-21 doi:10.1126/sciadv.abj0722 PMID: 34767452
  • Singh, P., K., Muqit M. M. (2020) Parkinson’s: A Disease of Aberrant Vesicle Trafficking Annu Rev Cell Dev Biol  Aug4. Doi: 10. 1146/annurev-cellbio-100818-125512. . Online ahead of print PMID: 32749865
  • Vieweg S, Mulholland K, Brauning B, Kacharia N, Lai YC, Toth R, Singh PK, Volpi I, Sattler M, Groll M, Itzen A, Muqit MMK (2020) PINK1-dependent phosphorylation of Serine111 within the SF3 motif of Rab GTPases impairs effector interactions and LRRK2 mediated phosphorylation at Threonine72 Biochem J  pii: BCJ20190664. doi: 10.1042/BCJ2019066 PMID: 32227113
  • McWilliams, T.G., Barini, E., Pohjolan-Pirhonen, R., Brooks, S.P., Singh, F., Burel, S., Balk, K., Kumar, A., Montava-Garriga, L., Prescott, A.R., Hassoun, S.M., Mouton-Liger, F., Ball, G., Hills, R., Knebel, A., Ulusoy, A., Di Monte, D.A., Tamjar, J., Fears, K., Smith, L., Brambila, R., Eerola-Rautio, J., Tienari, P., Corti, O., Dunnett, S.B., Ganley, I.G., Suomalainen, A., Muqit, M.M. (2018) Phosphorylation of Parkin serine 65 is essential for its activation in vivo. Open Biology 8: 180108. PMID: 30404819
  • Atul Kumar, Jevgenia Tamjar, Andrew D Waddell, Helen I Woodroof, Olawale G Raimi, Andrew M Shaw, Mark Peggie, Miratul MK Muqit, Daan MF van Aalten (2017) Structure of PINK1 and mechanisms of Parkinson's disease-associated mutations Elife. 6 pii: e29985 PMID: 28980524