Stimulation of translation by human Unr requires cold shock domains 2 and 4, and correlates with poly(A) binding protein interaction

The RNA binding protein Unr, which contains five cold shock domains, has several specific roles in post-transcriptional control of gene expression. It can act as an activator or inhibitor of translation initiation, promote mRNA turnover, or stabilise mRNA. Its role depends on the mRNA and other proteins to which it binds, which includes cytoplasmic poly(A) binding protein 1 (PABP1). Since PABP1 binds to all polyadenylated mRNAs, and is involved in translation initiation by interaction with eukaryotic translation initiation factor 4G (eIF4G), we investigated whether Unr has a general role in translational control. We found that Unr strongly stimulates translation in vitro, and mutation of cold shock domains 2 or 4 inhibited its translation activity. The ability of Unr and its mutants to stimulate translation correlated with its ability to bind RNA, and to interact with PABP1. We found that Unr stimulated the binding of PABP1 to mRNA, and that Unr was required for the stable interaction of PABP1 and eIF4G in cells. siRNA-mediated knockdown of Unr reduced the overall level of cellular translation in cells, as well as that of cap-dependent and IRES-dependent reporters. These data describe a novel role for Unr in regulating cellular gene expression

X chromosomal regulation in flies: when less is more

In Drosophila, dosage compensation of the single male X chromosome involves upregulation of expression of X linked genes. Dosage compensation complex or the male specific lethal (MSL) complex is intimately involved in this regulation. The MSL complex members decorate the male X chromosome by binding on hundreds of sites along the X chromosome. Recent genome wide analysis has brought new light into X chromosomal regulation. It is becoming increasingly clear that although the X chromosome achieves male specific regulation via the MSL complex members, a number of general factors also impinge on this regulation. Future studies integrating these aspects promise to shed more light into this epigenetic phenomenon

Long-term performance deterioration models for semi-rigid asphalt pavement in cold region

As the demand for the semi-rigid asphalt pavement reconstruction and maintenance technologies is increasing in the seasonal cold regions, the pavement performance deterioration models are essential for the success of the reconstruction and maintenance projects. This study is carried out to develop the deterioration models based on the preliminary investigation results of typical successful maintenances. All critical technical indexes concerning the asphalt pavement maintenance were studied. By combining the engineering practices, a long-term performance database of the semi-rigid asphalt pavement was established through a large amount of survey data, and the related environmental parameters. Based on the database achieved, the deterioration models of the semi-rigid asphalt pavement performances were built via the statistical regression method. It is concluded that the proposed deterioration models were useful and practical for the establishment of the maintenance decision of the semi-rigid asphalt pavements