Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P62988 (Ubiquitin)
 4,326 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Studies of familial forms of Parkinson's disease (PD) have identified a growing number of genes that derive from the loci given the nomenclature PARK1-PARK13 (OMIM 168600). The alpha-synuclein gene has been implicated in rare autosomal dominant PD because of either mis-sense mutations (PARK1) or gene multiplications (PARK4). Moreover, UCHL1 (PARK5), LRRK2 (PARK8) and HTRA2 (PARK13) have been identified as causative genes for autosomal dominant PD, whereas parkin (PARK2), PINK1 (PARK6), DJ-1 (PARK7) and ATP13A2 (PARK9) have been identified as causative genes for autosomal recessive PD. Neuropathological examination of the kindreds of PARK1/4 showed Lewy body pathology ranging from classic PD to diffuse Lewy body disease. The pathological findings of PARK3 are similar to those of classic PD. In contrast, autopsies of patients with PARK2 showed nigral cell loss without Lewy bodies, although exceptions have been reported. Several kindreds of PARK8 included cases with Lewy body pathology, tau pathology, or with nigral cell loss in the absence of obvious protein deposition. Ubiquitin-positive inclusions that are negative for alpha-synuclein and tau are also seen in some cases. Moreover, widespread Lewy body pathology was also reported in several cases of familial Alzheimer's disease with presenilin-1 mutations.
 ...
PMID:[Pathology of familial Parkinson's disease]. 1771 21

The PTEN-induced putative kinase protein 1 (PINK1) and ubiquitin (UB) ligase PARKIN direct damaged mitochondria for mitophagy. PINK1 promotes PARKIN recruitment to the mitochondrial outer membrane (MOM) for ubiquitylation of MOM proteins with canonical and noncanonical UB chains. PINK1 phosphorylates both Ser65 (S65) in the UB-like domain of PARKIN and the conserved Ser in UB itself, but the temporal sequence and relative importance of these events during PARKIN activation and mitochondria quality control remain poorly understood. Using "UB(S65A)-replacement," we find that PARKIN phosphorylation and activation, and ubiquitylation of Lys residues on a cohort of MOM proteins, occur similarly irrespective of the ability of the UB-replacement to be phosphorylated on S65. In contrast, polyubiquitin (poly-UB) chain synthesis, PARKIN retention on the MOM, and mitophagy are reduced in UB(S65A)-replacement cells. Analogous experiments examining roles of individual UB chain linkage types revealed the importance of K6 and K63 chain linkages in mitophagy, but phosphorylation of K63 chains by PINK1 did not enhance binding to candidate mitophagy receptors optineurin (OPTN), sequestosome-1 (p62), and nuclear dot protein 52 (NDP52) in vitro. Parallel reaction monitoring proteomics of total mitochondria revealed the absence of p-S65-UB when PARKIN cannot build UB chains, and <0.16% of the monomeric UB pool underwent S65 phosphorylation upon mitochondrial damage. Combining p-S65-UB and p-S65-PARKIN in vitro showed accelerated transfer of nonphosphorylated UB to PARKIN itself, its substrate mitochondrial Rho GTPase (MIRO), and UB. Our data further define a feed-forward mitochondrial ubiquitylation pathway involving PARKIN activation upon phosphorylation, UB chain synthesis on the MOM, UB chain phosphorylation, and further PARKIN recruitment and enzymatic amplification via binding to phosphorylated UB chains.
...
PMID:Defining roles of PARKIN and ubiquitin phosphorylation by PINK1 in mitochondrial quality control using a ubiquitin replacement strategy. 2596 9

The E3 ubiquitin ligase PARKIN (encoded by PARK2) and the protein kinase PINK1 (encoded by PARK6) are mutated in autosomal-recessive juvenile Parkinsonism (AR-JP) and work together in the disposal of damaged mitochondria by mitophagy. PINK1 is stabilized on the outside of depolarized mitochondria and phosphorylates polyubiquitin as well as the PARKIN ubiquitin-like (Ubl) domain. These phosphorylation events lead to PARKIN recruitment to mitochondria, and activation by an unknown allosteric mechanism. Here we present the crystal structure of Pediculus humanus PARKIN in complex with Ser65-phosphorylated ubiquitin (phosphoUb), revealing the molecular basis for PARKIN recruitment and activation. The phosphoUb binding site on PARKIN comprises a conserved phosphate pocket and harbours residues mutated in patients with AR-JP. PhosphoUb binding leads to straightening of a helix in the RING1 domain, and the resulting conformational changes release the Ubl domain from the PARKIN core; this activates PARKIN. Moreover, phosphoUb-mediated Ubl release enhances Ubl phosphorylation by PINK1, leading to conformational changes within the Ubl domain and stabilization of an open, active conformation of PARKIN. We redefine the role of the Ubl domain not only as an inhibitory but also as an activating element that is restrained in inactive PARKIN and released by phosphoUb. Our work opens up new avenues to identify small-molecule PARKIN activators.
...
PMID:Mechanism of phospho-ubiquitin-induced PARKIN activation. 2641 42