Volume 8 Issue 7, July 2006

Precise spatial regulation of mRNA remodelling is crucial for proper gene expression. One way this is accomplished is through activation of the DEAD-box helicase Dbp5 at the cytoplasmic fibrils of the nuclear-pore complex, by the nucleoporin Gle1 and the soluble inositol polyphosphate InsP₆.

The general amino acids permease Gap1p provides yeast with sufficient amino acids to maintain protein synthesis. Gap1p is translocated to the plasma membrane when amino acids become limiting, a process that is mediated by a newly identified membrane complex called the GSE complex.

Actin and actin-binding factors have been implicated in nuclear processes such as chromatin remodelling, mRNA processing and export, and transcription. Until now, actin was assumed to function in these processes as a monomer; however, new work suggests that polymerized actin and its effectors may also be important, particularly in transcription.

The mode of propagation of the centrosome has suggested the participation of nucleic acid but four decades of inquiry have been inconclusive. A recent study has provided evidence that centrosomes isolated from clam oocytes are associated with specific RNAs, at least one of which seems to be an mRNA.

Rises in cytoplasmic Ca²⁺ concentration control a diverse array of key cellular functions. One ubiquitous route for raising Ca²⁺ concentration is through store-operated calcium channels in the plasma membrane. However, the molecular basis of store-operated entry has remained a mystery. Now, exciting new research may have identified the molecular composition of a store-operated channel.