In the yeast commitment complex and the mammalian E complex, there is an important base-pairing interaction between the 5' end of U1 snRNA and the conserved 5' splice site region of pre-mRNA. But no protein contacts between splicing proteins and the pre-mRNA substrate have been defined in or near this region of early splicing complexes. To address this issue, we used 4-thiouridine-substituted 5...

In the larval salivary glands of C. tentans, it is possible to visualize by electron microscopy how Balbiani ring (BR) pre-mRNA associates with proteins to form pre-mRNP particles, how these particles move to and through the nuclear pore, and how the BR RNA is engaged in the formation of giant polysomes in the cytoplasm. Here, we study C. tentans hrp36, an abundant protein in the BR particles, ...

Commitment complexes contain U1 snRNP as well as pre-mRNA and are the earliest functional complexes that have been described during in vitro spliceosome assembly. We have used a gel retardation assay to analyze the role of the yeast pre-mRNA cis-acting sequences in commitment complex formation. The results suggest that only a proper 5' splice site sequence is required for efficient U1 snRNA-pre...

in this work, we report synthesis and characterization of copper nanoparticles in polymer matrix by wet-chemical reduction method using ascorbic acid as reducing agent, copper (ii) sulfate as metal precursor and polyvinylpyrrolidone k-30 (pvp k-30) as surfactant agent. the reaction was carried out in a high-speed stirring mixture at room temperature under nitrogen atmosphere. characterization o...

carbon membrane can be produced using a wide variety of polymer precursor materials via heat treatment process. a general concept route of precursor selection-preparation-modification-performance analysis platform for the carbon membrane has been proposed to promote the development of carbon membrane material for a wide range of application. the current review considers the recent progress of c...