In this study, we isolated a cDNA for tetrameric carbonyl reductase (CR) from pig heart. The pig CR showed high amino acid sequence identity (81%) with rabbit NADP(+)-dependent retinol dehydrogenase (NDRD). The purified recombinant pig CR and NDRD were about 100-kDa homotetramers and exhibited high reductase activity towards alkyl phenyl ketones, alpha-dicarbonyl compounds and all-trans-retinal. The identity of NDRD with the tetrameric CR was verified by protein sequencing of CR purified from rabbit heart. Both tetrameric CR and its mRNA were ubiquitously expressed in pig and rabbit tissues. The pig and rabbit enzymes belonged to the short-chain dehydrogenase/reductase family, and their sequences comprise a C-terminal SRL tripeptide, which is a variant of the type 1 peroxisomal targeting signal, SKL. Transfection of HeLa cells with vectors expressing pig CR demonstrated that the enzyme is localized in the peroxisomes. Thus, the tetrameric form of CR represents the first mammalian peroxisomal enzyme that reduces all-trans-retinal as the endogenous substrate.
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http://dx.doi.org/10.1016/s0009-2797(02)00210-7 | DOI Listing |
Cell
December 2024
Department of Biochemistry, University of Zurich, Zurich, Switzerland. Electronic address:
The detection of molecular patterns associated with invading pathogens is a hallmark of innate immune systems. Prokaryotes deploy sophisticated host defense mechanisms in innate anti-phage immunity. Shedu is a single-component defense system comprising a putative nuclease SduA.
View Article and Find Full Text PDFJ Mol Graph Model
December 2024
Mohammed VI University of Sciences and Health, UM6SS, Morocco; Mohammed VI Center for Research and Innovation, (CM6RI), Morocco. Electronic address:
PqsE and RhlR, key regulators of the Pseudomonas aeruginosa quorum sensing (QS) system, form a hetero-tetrameric complex essential for controlling the expression of virulence factors such as pyocyanin. The interaction between the PqsE homodimer and the RhlR homodimer bound to C4-HSL, enables RhlR to bind low-affinity promoters, thereby influencing gene regulation. Recent studies suggest that RhlR transcriptional activity is modulated by temperature, exhibiting higher activity at environmental temperatures (25 °C) compared to mammalian body temperature (37 °C).
View Article and Find Full Text PDFBiochem Biophys Res Commun
December 2024
State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin, 300071, China. Electronic address:
Mammalian SWI/SNF (mSWI/SNF) ATP-dependent chromatin remodeling complexes play critical roles in regulating gene expression and DNA accessibility, and more than 20 % of cancers have mutations in genes encoding chromatin remodeling complexes. The mSWI/SNF family comprises three distinct classes: canonical BAF (cBAF), PBAF, and non-canonical BAF (ncBAF). While the structures of cBAF and PBAF have been resolved by using cryo-electron microscopy (cryo-EM), the modular organization and assembly mechanism of ncBAF remain poorly understood.
View Article and Find Full Text PDFSci Rep
December 2024
School of Biological Sciences, University of Utah, Salt Lake City, Utah, USA.
Voltage-gated potassium channels (VGKCs) comprise the largest and most complex families of ion channels. Approximately 70 genes encode VGKC alpha subunits, which assemble into functional tetrameric channel complexes. These subunits can also combine to form heteromeric channels, significantly expanding the potential diversity of VGKCs.
View Article and Find Full Text PDFProtein Sci
January 2025
Institute of Evolutionary Biology, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland.
Coiled coils are a common protein structural motif involved in cellular functions ranging from mediating protein-protein interactions to facilitating processes such as signal transduction or regulation of gene expression. They are formed by two or more alpha helices that wind around a central axis to form a buried hydrophobic core. Various forms of coiled-coil bundles have been reported, each characterized by the number, orientation, and degree of winding of the constituent helices.
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