scholarly journals Molecular Characterization of PGC-1β (PPAR Gamma Coactivator 1β) and its Roles in Mitochondrial Biogenesis in Blunt Snout Bream (Megalobrama amblycephala)

2020 ◽  
Vol 21 (6) ◽  
pp. 1935 ◽  
Author(s):  
Kangle Lu ◽  
Tomas Policar ◽  
Xiaojun Song ◽  
Samad Rahimnejad
Keyword(s):  
Molecular Characterization ◽  
Mitochondrial Biogenesis ◽  
Phylogenetic Analyses ◽  
Ppar Gamma ◽  
Megalobrama Amblycephala ◽  
Fat Intake ◽  
High Fat ◽  
Blunt Snout Bream ◽  
Mitochondria Biogenesis

This study aimed at achieving the molecular characterization of peroxisome proliferator-activated receptor-gamma coactivator 1β (PGC-1β) and exploring its modulatory roles in mitochondria biogenesis in blunt snout bream (Megalobrama amblycephala). A full-length cDNA of PGC-1β was cloned from liver which covered 3110 bp encoding 859 amino acids. The conserved motifs of PGC-1β family proteins were gained by MEME software, and the phylogenetic analyses showed motif loss and rearrangement of PGC-1β in fish. The function of PGC-1β was evaluated through overexpression and knockdown of PGC-1β in primary hepatocytes of blunt snout bream. We observed overexpression of PGC-1β along with enhanced mitochondrial transcription factor A (TFAM) expression and mtDNA copies in hepatocytes, and its knockdown led to slightly reduced NRF1 expression. However, knockdown of PGC-1β did not significantly influence TFAM expression or mtDNA copies. The alterations in mitochondria biogenesis were assessed following high-fat intake, and the results showed that it induces downregulation of PGC-1β. Furthermore, significant decreases in mitochondrial respiratory chain activities and mitochondria biogenesis were observed by high-fat intake. Our findings demonstrated that overexpression of PGC-1β induces the enhancement of TFAM expression and mtDNA amount but not NRF-1. Therefore, it could be concluded that PGC-1β is involved in mitochondrial biogenesis in blunt snout bream but not through PGC-1β/NRF-1 pathway.

scholarly journals Functional and Molecular Characterization of the Halomicrobium sp. IBSBa Inulosucrase

2021 ◽  
Vol 9 (4) ◽  
pp. 749
Author(s):  
Gülbahar Abaramak ◽  
Jaime Ricardo Porras-Domínguez ◽  
Henry Christopher Janse van Rensburg ◽  
Eveline Lescrinier ◽  
Ebru Toksoy Öner ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Phylogenetic Analyses ◽  
Halophilic Archaea ◽  
Maximum Activity ◽  
Physiological Relevance ◽  
Health Related ◽  
Specific Alternative ◽  
Binding Groove ◽  
Native Host

Fructans are fructose-based (poly)saccharides with inulin and levan being the best-known ones. Thanks to their health-related benefits, inulin-type fructans have been under the focus of scientific and industrial communities, though mostly represented by plant-based inulins, and rarely by microbial ones. Recently, it was discovered that some extremely halophilic Archaea are also able to synthesize fructans. Here, we describe the first in-depth functional and molecular characterization of an Archaeal inulosucrase from Halomicrobium sp. IBSBa (HmcIsc). The HmcIsc enzyme was recombinantly expressed and purified in Escherichia coli and shown to synthesize inulin as proven by nuclear magnetic resonance (NMR) analysis. In accordance with the halophilic lifestyle of its native host, the enzyme showed maximum activity at very high NaCl concentrations (3.5 M), with specific adaptations for that purpose. Phylogenetic analyses suggested that Archaeal inulosucrases have been acquired from halophilic bacilli through horizontal gene transfer, with a HX(H/F)T motif evolving further into a HXHT motif, together with a unique D residue creating the onset of a specific alternative acceptor binding groove. This work uncovers a novel area in fructan research, highlighting unexplored aspects of life in hypersaline habitats, and raising questions about the general physiological relevance of inulosucrases and their products in nature.

Sign in / Sign up

Export Citation Format

Share Document