Neuronal growth regulator 1 promotes adipocyte lipid trafficking via interaction with CD36

Neuronal growth regulator 1 (NEGR1) is a glycosylphosphatidylinositol-anchored membrane protein associated with several human pathologies, including obesity, depression, and autism. Recently, significantly enlarged white adipose tissue, hepatic lipid accumulation, and decreased muscle capacity were reported in Negr1-deficient mice. However, the mechanism behind these phenotypes was not clear. In the present study, we found NEGR1 to interact with cluster of differentiation 36 (CD36), the major fatty acid translocase in the plasma membrane. Binding assays with a soluble form of NEGR1 and in situ proximal ligation assays indicated that NEGR1-CD36 interaction occurs at the outer leaflet of the cell membrane. Furthermore, we show that NEGR1 overexpression induced CD36 protein destabilization in vitro. Both mRNA and protein levels of CD36 were significantly elevated in the white adipose tissue and liver tissues of Negr1^?/? mice. Accordingly, fatty acid uptake rate increased in NEGR1-deficient primary adipocytes. Finally, we demonstrated that Negr1^?/? mouse embryonic fibroblasts showed elevated reactive oxygen species levels and decreased adenosine monophosphate-activated protein kinase activation compared with control mouse embryonic fibroblasts. Based on these results, we propose that NEGR1 regulates cellular fat content by controlling the expression of CD36.     

Back Cover: Characterization and application of porous gold nanoparticles as 2‐photon luminescence imaging agents: 20‐fold brighter than gold nanorods (J. Biophotonics 2/2018)

Gold nanoparticles serve as imaging contrast agents useful for two‐photon nonlinear microscopy of biological cells and tissues. In this study, 100‐nm‐sized gold particles with a multitude of nanopores embedded inside have been physically synthesized and investigated for the plasmonic enhancement in two‐photon luminescence. Exhibiting remarkable potential for two‐photon imaging, the porous gold nanoparticles boost near‐infrared light absorption substantially and allow emission signals 20 times brighter than gold nanorods being currently used as typical imaging agents. Further details can be found in the article by Joo H. Park et al. ( e201700174 )

     

Cold shock domain proteins and glycine-rich RNA-binding proteins from Arabidopsis thaliana can promote the cold adaptation process in Escherichia coli

Despite the fact that cold shock domain proteins (CSDPs) and glycine-rich RNA-binding proteins (GRPs) have been implicated to play a role during the cold adaptation process, their importance and function in eukaryotes, including plants, are largely unknown. To understand the functional role of plant CSDPs and GRPs in the cold response, two CSDPs (CSDP1 and CSDP2) and three GRPs (GRP2, GRP4 and GRP7) from Arabidopsis thaliana were investigated. Heterologous expression of CSDP1 or GRP7 complemented the cold sensitivity of BX04 mutant Escherichia coli that lack four cold shock proteins (CSPs) and is highly sensitive to cold stress, and resulted in better survival rate than control cells during incubation at low temperature. In contrast, CSDP2 and GRP4 had very little ability. Selective evolution of ligand by exponential enrichment (SELEX) revealed that GRP7 does not recognize specific RNAs but binds preferentially to G-rich RNA sequences. CSDP1 and GRP7 had DNA melting activity, and enhanced RNase activity. In contrast, CSDP2 and GRP4 had no DNA melting activity and did not enhance RNAase activity. Together, these results indicate that CSDPs and GRPs help E.coli grow and survive better during cold shock, and strongly imply that CSDP1 and GRP7 exhibit RNA chaperone activity during the cold adaptation process.     

In situ egg production rate of the planktonic copepod Acartia steueri in Ilkwang Bay, southeastern coast of Korea

Egg production rate (EPR) of the copepod Acartia steueri wasinvestigated by in situ incubation in Ilkwang Bay, Korea. EPRranged from 3.8 to 10.1 eggs female^–1 d^–1, and weight-specificgrowth rate decreased with increasing body weight of the adultfemale.