Anti-Ubiquitin (N-terminal) polyclonal antibody

The Drosophila Slimb (Slmb) gene encodes a Skpl-Cull-F-box (SCP) E3 ubiquitin ligase orthologous to the human beta-TrCP/BTRC protein. Slmb and/or BTRC play regulatory roles in numerous biological processes by ubiquitinating several substrate proteins which are then targeted for proteasomal degradation. Here, we demonstrate an additional role for Slmb in maintaining cellular copper homeostasis. In the thorax, midgut and eye, Slmb knockdown causes copper deficiency phenotypes which can be rescued by increasing cellular copper levels via decreased efflux or increased uptake. Furthermore, Slmb knockdown results in decreased levels of the copper transporters Ctr1A and ATP7, indicating Slmb is required to regulate copper homeostasis. We also present evidence that the transcription factor Cap-n-Collar (Nrf2 in mammals), a known substrate of Slmb/BTRC, mediates Slmb's regulatory effect on Ctr1A in a post-transcriptional manner.

Objective: The aim of the present study was to investigate the biological roles and underlying mechanism of the long non-coding RNA maternally expressed gene 3 (MEG3) on osteogenic differentiation of human dental pulp stem cells (hDPSCs). Methods: The expression levels of MEG3, microRNA-543 (miR-543), osterix, osteopontin, osteocalcin and runt-related transcription factor 2 (RUNX2) were measured by quantitative real-time PCR (qRT-PCR). Alkaline phosphatase (ALP) activity assay and alizarin red S staining (ARS) were used to measure the impacts exerted by MEG3, miR-543 on osteogenic differentiation. Cell proliferation was measured by MTT assay. In addition, the targeted relationships between miR-543, MEG3, and Smad ubiquitin regulatory factor 1 (SMURF1) were assessed through dual luciferase reporter assay. Results: During osteogenic induction, the expression of MEG3 was gradually reduced, whereas the expression of miR-543, osterix, osteopontin, osteocalcin and RUNX2 were gradually increased. Functional analysis implied that MEG3 overexpression or miR-543 inhibition reduced the cell proliferation, ALP activity, ARS levels, and decreased the expression of osteoblast-related proteins. Moreover, MEG3 promoted SMURF1 expression by directly targeting miR-543 as a competing endogenous RNA. Furthermore, overexpression of miR-543 or silencing SMURF1 could reverse the inhibitory effects of MEG3 on the osteogenic differentiation of hDPSCs. Conclusions: In conclusion, our study revealed that overexpression of MEG3 inhibited hDPSCs osteogenic differentiation via miR-543/SMURF1/RUNX2 regulatory network, which may contribute to the functional regulation and clinical applications of hDPSCs.