A5031071553- Ubiquitin and proteasome pathways
- Cancer-related Molecular Pathways
- Nitric Oxide and Endothelin Effects
- Protein Degradation and Inhibitors
- Cancer, Hypoxia, and Metabolism
- Autophagy in Disease and Therapy
- Amino Acid Enzymes and Metabolism
- Alzheimer's disease research and treatments
- Histone Deacetylase Inhibitors Research
- Glycosylation and Glycoproteins Research
- Electron Spin Resonance Studies
- Genetics and Neurodevelopmental Disorders
- Hemoglobin structure and function
- Photosynthetic Processes and Mechanisms
- Analytical Chemistry and Sensors
- RNA modifications and cancer
- Receptor Mechanisms and Signaling
- S100 Proteins and Annexins
- Protein Structure and Dynamics
- Metal-Catalyzed Oxygenation Mechanisms
- Renin-Angiotensin System Studies
- Machine Learning in Bioinformatics
- DNA Repair Mechanisms
- Genomics and Chromatin Dynamics
- Biotin and Related Studies
Clark University
2016-2024
Western University
2010-2019
University of Waterloo
2004-2012
Abstract The PARK 2 gene is mutated in 50% of autosomal recessive juvenile parkinsonism ( ARJP ) cases. It encodes parkin, an E3 ubiquitin ligase the RBR family. Parkin exists autoinhibited state that activated by phosphorylation its N‐terminal ubiquitin‐like (Ubl) domain and binding phosphoubiquitin. We describe 1.8 Å crystal structure human parkin fully inhibited identify key interfaces to maintain inhibition. phosphoubiquitin‐binding interface, provide a model for phosphoubiquitin–parkin...
Mutations in the park2 gene, encoding RING-inBetweenRING-RING E3 ubiquitin ligase parkin, cause 50% of autosomal recessive juvenile Parkinsonism cases. More than 70 known pathogenic mutations occur throughout many which cluster inhibitory amino-terminal ubiquitin-like domain, and carboxy-terminal RING2 domain that is indispensable for transfer. A structural rationale showing how alter parkin function still lacking. Here we show structure distinct from canonical RING ligases lacks key...
Maintaining genomic stability and properly repairing damaged DNA is essential to staying healthy preserving cellular homeostasis. The five major pathways involved in eukaryotic include base excision repair (BER), nucleotide (NER), mismatch (MMR), non-homologous end joining (NHEJ), homologous recombination (HR). When these do not DNA, compromised can contribute diseases such as cancer. It that the causes of damage consequent are fully understood, yet initial recruitment regulation response...
Significance Interactions between E2 and E3 enzymes are key for ubiquitination, but whether such a dynamic association is susceptible to perturbation by small-molecule modulators remains elusive. By demonstrating that suramin can inhibit cullin-RING ubiquitin ligase disrupting its ability recruit Cdc34, this work suggests the E2–E3 interface may be druggable. In addition, an antitrypansomal drug also possesses antitumor activity. Our findings have linked ubiquitin-proteasome pathway suggest...
Calmodulin (CaM) is a Ca2+ signal transducing protein that binds and activates many cellular enzymes with physiological relevance, including the mammalian nitric oxide synthase (NOS) isozymes: endothelial NOS (eNOS), neuronal (nNOS), inducible (iNOS). The mechanism of CaM binding activation to iNOS enzyme poorly understood in part due strength bound complex difficulty assessing role played by regions outside CaM-binding domain. To further elucidate these processes, we have developed...
Nitric oxide synthase (NOS) plays a major role in number of key physiological and pathological processes. Knowledge how this is regulated important. The small acidic calcium binding protein, calmodulin (CaM), required to fully activate the enzyme. exact mechanism CaM activates NOS not understood. Studies have shown act like switch that causes conformational change allow for transfer an electron between reductase oxygenase domains through process thought be highly dynamic. To investigate...
The interactions of neuronal nitric-oxide synthase (nNOS) with calmodulin (CaM) and mutant forms CaM, including CaM-troponin C chimeras, have been previously reported, but there has no comparable investigation CaM the other constitutively expressed NOS (cNOS), endothelial (eNOS), or inducible isoform (iNOS). present study was designed to evaluate role four EF hands in activation eNOS iNOS. To assess regions on aspects enzymatic function, three distinct activities associated were measured:...
Calmodulin (CaM) is a cytosolic Ca(2+) signal-transducing protein that binds and activates many different cellular enzymes with physiological relevance, including the nitric oxide synthase (NOS) isozymes. CaM consists of two globular domains joined by central linker; each domain contains an EF hand pair. Four mutant proteins were used to investigate role pairs in binding activation mammalian inducible NOS (iNOS) constitutive (cNOS) enzymes, endothelial (eNOS) neuronal (nNOS). The aspects...
Significance Our identification and characterization of the ubiquitin (Ub) Y59-E51 loop have uncovered a pivotal determinant for lysine 48 (K48) linkage-specific Ub chain synthesis catalyzed by Cdc34 E2 Ub-conjugating enzyme. The appears to anchor E2-engaging zone, allowing landing enabling it gain access receptor K48. These findings will provide strong starting point future biochemical structural studies aiming elucidate detailed interactions between E2/E3 enzymes that produce K48 linkage....
The assembly of proteins into dimers and oligomers is a necessary step for the proper function transcription factors, muscle proteins, proteases. In uncontrolled states, oligomerization can also contribute to illnesses such as Alzheimer's disease. S100 protein family group dimeric that have important roles in enzyme regulation, cell membrane repair, growth. Most been examined their homodimeric state, yet some these are found similar tissues implying heterodimeric molecules be formed from...
Alzheimer's disease (AD), the most common cause of dementia in elderly, is sixth leading death United States. We hypothesize that impaired clearance Aβ42 from brain partly responsible for onset sporadic AD. In this work, we evaluated activity insulin-degrading enzyme (IDE) toward presence resveratrol, a polyphenol found red wine and grape juice. By liquid chromatography/mass spectrometry, identified initial cleavage sites absence resveratrol carry biological relevance connected to...
The ubiquitin-signaling pathway utilizes E1 activating, E2 conjugating, and E3 ligase enzymes to sequentially transfer the small modifier protein ubiquitin a substrate protein. During last step of this cascade different types ligases either act as scaffolds recruit an enzyme (RING), or form ubiquitin-thioester intermediate prior transferring (HECT). RING-inBetweenRING-RING (RBR) proteins constitute unique group that includes Human Homologue Drosophila Ariadne (HHARI). These are proposed use...
The HECT-type ubiquitin ligase E6AP (UBE3A) is critically involved in several neurodevelopmental disorders and human papilloma virus-induced cervical tumorigenesis; the structural mechanisms underlying activity of this crucial ligase, however, are incompletely understood. Here, we report a crystal structure C-terminal lobe ("C-lobe") catalytic domain that reveals two molecules domain-swapped, dimeric arrangement. Interestingly, molecular hinge enables reorganization with respect to monomeric...
We have explored the mechanisms of polyubiquitin chain assembly with reconstituted ubiquitination IκBα and β-catenin by Skp1-cullin 1-βTrCP F-box protein (SCFβTrCP) E3 ubiquitin (Ub) ligase complex. Competition experiments revealed that SCFβTrCP formed a complex Nedd8 modified E3-substrate platform engaged in dynamic interactions Cdc34 E2 Ub conjugating enzyme for elongation. Using “elongation intermediates” containing linked chains defined length, it was observed Lys-48-Ub length greater...