COV-Drug Target interaction server for Covid-19 Drug Repurposing

The outbreak of the novel coronavirus disease COVID-19, caused by the SARS-CoV-2 virus has killed over 5 million people to date. So, there is an urgent requirement for new and effective medications that can treat the disease caused by SARS-CoV-2. To find new drugs, identification of drug targets is necessary (Chen et al., 2016). Number of research studies have identified therapeutic targets such as helicases, transmembrane serine protease 2, cathepsin L, cyclin G-associated kinase, adaptor associated kinase 1, two-pore channel, viral virulence factors, 3-chymotrypsin-like protease, suppression of excessive inflammatory response, inhibition of viral membrane, nucleocapsid, envelope, and accessory proteins, and inhibition of endocytosis. Here we present a web enabled tool which helps in ranking the COVID-19 drugs based upon underlying molecular targets. The users are allowed to give drugs in SMILE format and the tools will provide the list of relevant targets related to COVID-19.

GAK and PRKCD are positive regulators of PRKN-independent mitophagy

The mechanisms involved in programmed or damage-induced removal of mitochondria by mitophagy remains elusive. Here, we have screened for regulators of PRKN-independent mitophagy using an siRNA library targeting 197 proteins containing lipid interacting domains. We identify Cyclin G-associated kinase (GAK) and Protein Kinase C Delta (PRKCD) as regulators of PRKN-independent mitophagy, with both being dispensable for PRKN-dependent mitophagy and starvation-induced autophagy. We demonstrate that the kinase activity of both GAK and PRKCD are required for efficient mitophagy in vitro, that PRKCD is present on mitochondria, and that PRKCD facilitates recruitment of ULK1/ATG13 to early autophagic structures. Importantly, we demonstrate in vivo relevance for both kinases in the regulation of basal mitophagy. Knockdown of GAK homologue (gakh-1) in C. elegans or knockout of PRKCD homologues in zebrafish led to significant inhibition of basal mitophagy, highlighting the evolutionary relevance of these kinases in mitophagy regulation.

Cyclin-G-associated kinase GAK/Aux orchestrates glial autophagy via Atg9 phosphorylation in Parkinson's disease

Glia serve as double-edged swords to modulate neuropathology in Parkinson's disease (PD), but how they react opposingly to be beneficial or detrimental under pathological conditions, like promote or eliminate α-Synuclein inclusions, remain elusive. Here we present evidence that the PD risk factor Cyclin G-associated kinase (GAK)/dAuxilin (Aux) is a new component in glial autophagy. Lack of GAK/Aux promotes autophagic induction, disrupts lysosome acidification, and blocks glial clearance of substrates. Aux regulates Atg9 trafficking to autophagosomes and lysosomes for autophagosome biogenesis and autolysosome maturation, respectively, via Atg9 phosphorylation at newly identified residues T62 and T69. GAK/Aux-mediated glial autophagy is required for α-Syn degradation and contributes to a broad spectrum of parkinsonian symptoms in Drosophila and mice. Our findings indicate that glial autophagy is a critical component in PD progression and identify a new autophagy factor functioning in a tissue-specific manner; targeting glial autophagy is potentially a therapeutic solution for PD.

GAK and PRKCD are positive regulators of PRKN-independent mitophagy

ABSTRACTThe mechanisms involved in programmed or damage-induced removal of mitochondria by mitophagy in response to different stimuli remains elusive. Here, we have screened for regulators of PRKN-independent mitophagy using an siRNA library targeting 197 proteins containing lipid interacting domains. We identify Cyclin G-associated kinase (GAK) and Protein Kinase C Delta (PRKCD) as novel regulators of PRKN-independent mitophagy, with both being dispensable for PRKN-dependent mitophagy and starvation-induced autophagy. We demonstrate that the kinase activity of both GAK and PRKCD are required for efficient mitophagy in vitro, that PRKCD is present on mitochondria, and that PRKCD is required for ULK1/ATG13 recruitment to early autophagic structures. Importantly, we demonstrate in vivo relevance for both kinases in the regulation of basal mitophagy. Knockdown of GAK homologue (gakh-1) in C.elegans or PRKCD homologues in zebrafish led to significant inhibition of basal mitophagy, highlighting the evolutionary relevance of these kinases in mitophagy.

Targeting the water network in cyclin G associated kinase (GAK) with 4-anilino-quin(az)oline inhibitors

Water networks within kinase inhibitor design and more widely within drug discovery are generally poorly understood. The successful targeting of these networks prospectively has great promise for all facets of inhibitor design, including potency and selectivity on target. Here we describe the design and testing of a targeted library of 4-anilinoquinolines for use as inhibitors of cyclin G associated kinase (GAK). The GAK cellular target engagement assays, ATP binding site modelling and extensive water mapping provide a clear route to access potent inhibitors for GAK and beyond.

Towards the Development of an In vivo Chemical Probe for Cyclin G Associated Kinase (GAK)

SGC-GAK-1 (1) is a potent, selective, cell-active chemical probe for cyclin G-associated kinase (GAK). However, 1 was rapidly metabolized in mouse liver microsomes by cytochrome P450-mediated oxidation, displaying rapid clearance in liver microsomes and in mice, which limited its utility in in vivo studies. Chemical modifications of 1 that improved metabolic stability, generally resulted in decreased GAK potency. The best analog in terms of GAK activity in cells was 6-bromo-N-(1H-indazol-6-yl)quinolin-4-amine (35) (IC50 = 1.4 μM), showing improved stability in liver microsomes while still maintaining a narrow spectrum activity across the kinome. As an alternative to scaffold modifications we also explored the use of the broad-spectrum cytochrome P450 inhibitor 1-aminobenzotriazole (ABT) to decrease intrinsic clearance of aminoquinoline GAK inhibitors. Taken together, these approaches point towards the development of an in vivo chemical probe for the dark kinase GAK.