scholarly journals Loss of UCHL1 rescues the defects related to Parkinson’s disease by suppressing glycolysis

2021 ◽  
Vol 7 (28) ◽  
pp. eabg4574
Author(s):  
Su Jin Ham ◽  
Daewon Lee ◽  
Wen Jun Xu ◽  
Eunjoo Cho ◽  
Sekyu Choi ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Protein Kinase ◽  
Pyruvate Kinase ◽  
Mammalian Cells ◽  
Loss Of Function ◽  
Tripartite Motif ◽  
Carboxyl Terminal ◽  
Amp Activated Protein Kinase

The role of ubiquitin carboxyl-terminal hydrolase L1 (UCHL1; also called PARK5) in the pathogenesis of Parkinson’s disease (PD) has been controversial. Here, we find that the loss of UCHL1 destabilizes pyruvate kinase (PKM) and mitigates the PD-related phenotypes induced by PTEN-induced kinase 1 (PINK1) or Parkin loss-of-function mutations in Drosophila and mammalian cells. In UCHL1 knockout cells, cellular pyruvate production and ATP levels are diminished, and the activity of AMP–activated protein kinase (AMPK) is highly induced. Consequently, the activated AMPK promotes the mitophagy mediated by Unc-51–like kinase 1 (ULK1) and FUN14 domain–containing 1 (FUNDC1), which underlies the effects of UCHL1 deficiency in rescuing PD-related defects. Furthermore, we identify tripartite motif–containing 63 (TRIM63) as a previously unknown E3 ligase of PKM and demonstrate its antagonistic interaction with UCHL1 to regulate PD-related pathologies. These results suggest that UCHL1 is an integrative factor for connecting glycolysis and PD pathology.

scholarly journals Parkin is recruited selectively to impaired mitochondria and promotes their autophagy

2008 ◽  
Vol 183 (5) ◽  
pp. 795-803 ◽  
Author(s):  
Derek Narendra ◽  
Atsushi Tanaka ◽  
Der-Fen Suen ◽  
Richard J. Youle
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Mammalian Cells ◽  
Loss Of Function ◽  
Gene Coding ◽  
Selective Elimination ◽  
Mitochondrial Toxins ◽  
Early Onset Parkinson’S Disease ◽  
Increased Susceptibility

Loss-of-function mutations in Park2, the gene coding for the ubiquitin ligase Parkin, are a significant cause of early onset Parkinson's disease. Although the role of Parkin in neuron maintenance is unknown, recent work has linked Parkin to the regulation of mitochondria. Its loss is associated with swollen mitochondria and muscle degeneration in Drosophila melanogaster, as well as mitochondrial dysfunction and increased susceptibility to mitochondrial toxins in other species. Here, we show that Parkin is selectively recruited to dysfunctional mitochondria with low membrane potential in mammalian cells. After recruitment, Parkin mediates the engulfment of mitochondria by autophagosomes and the selective elimination of impaired mitochondria. These results show that Parkin promotes autophagy of damaged mitochondria and implicate a failure to eliminate dysfunctional mitochondria in the pathogenesis of Parkinson's disease.

scholarly journals How treatments with endocrine and metabolic drugs influence pituitary cell function

2020 ◽  
Vol 9 (2) ◽  
pp. R14-R27 ◽  
Author(s):  
Giovanni Tulipano
Keyword(s):  
Protein Kinase ◽  
Mammalian Cells ◽  
Cell Function ◽  
Cell Metabolism ◽  
Cell Signalling ◽  
Pituitary Cell ◽  
Pituitary Cells ◽  
Transduction Mechanisms ◽  
Amp Activated Protein Kinase

A variety of endocrine and metabolic signals regulate pituitary cell function acting through the hypothalamus-pituitary neuroendocrine axes or directly at the pituitary level. The underlying intracellular transduction mechanisms in pituitary cells are still debated. AMP-activated protein kinase (AMPK) functions as a cellular sensor of low energy stores in all mammalian cells and promotes adaptive changes in response to calorie restriction. It is also regarded as a target for therapy of proliferative disorders. Various hormones and drugs can promote tissue-specific activation or inhibition of AMPK by enhancing or inhibiting AMPK phosphorylation, respectively. This review explores the preclinical studies published in the last decade that investigate the role of AMP-activated protein kinase in the intracellular transduction pathways downstream of endocrine and metabolic signals or drugs affecting pituitary cell function, and its role as a target for drug therapy of pituitary proliferative disorders. The effects of the hypoglycemic agent metformin, which is an indirect AMPK activator, are discussed. The multiple effects of metformin on cell metabolism and cell signalling and ultimately on cell function may be either dependent or independent of AMPK. The in vitro effects of metformin may also help highlighting differences in metabolic requirements between pituitary adenomatous cells and normal cells.

scholarly journals Role of Cleaved PINK1 in Neuronal Development, Synaptogenesis, and Plasticity: Implications for Parkinson’s Disease

2021 ◽  
Vol 15 ◽  
Author(s):  
Smijin K. Soman ◽  
Ruben K. Dagda
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Neuronal Development ◽  
Structural Integrity ◽  
Intermembrane Space ◽  
Loss Of Function ◽  
Serine Threonine Kinase ◽  
Functional Roles ◽  
Neuronal Functions

Mitochondrial dysfunction plays a significant role in the pathogenesis of Parkinson’s disease (PD). Consistent with this concept, loss of function mutations in the serine/threonine kinase- PINK1 (PTEN-induced putative kinase-1) causes autosomal recessive early onset PD. While the functional role of f-PINK1 (full-length PINK1) in clearing dysfunctional mitochondria via mitophagy is extensively documented, our understanding of specific physiological roles that the non-mitochondrial pool of PINK1 imparts in neurons is more limited. PINK1 is proteolytically processed in the intermembrane space and matrix of the mitochondria into functional cleaved products (c-PINK1) that are exported to the cytosol. While it is clear that posttranslational processing of PINK1 depends on the mitochondria’s oxidative state and structural integrity, the functional roles of c-PINK1 in modulating neuronal functions are poorly understood. Here, we review the diverse roles played by c-PINK1 in modulating various neuronal functions. Specifically, we describe the non-canonical functional roles of PINK1, including but not limited to: governing mitochondrial movement, neuronal development, neuronal survival, and neurogenesis. We have published that c-PINK1 stimulates neuronal plasticity and differentiation via the PINK1-PKA-BDNF signaling cascade. In addition, we provide insight into how mitochondrial membrane potential-dependent processing of PINK1 confers conditional retrograde signaling functions to PINK1. Further studies delineating the role of c-PINK1 in neurons would increase our understanding regarding the role played by PINK1 in PD pathogenesis.

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