Proteomic code

On the basis of recent fundamentally novel developments in the protein structure a proteomic code is suggested, that would potentially allow to describe sequence, structure, and function of proteins by a spectrum of elementary loop-n-lock units. All major characteristics of the nearly standard units are described, and first five "codons" of the proteomic code are presented with their respective unique sequences, structures, and functions. More such codons are to be discovered, and the general procedure for their identification is described.     

The genetic code, an instantaneous absolutely optimal code

The genetic code is an instantaneous code i.e., each codon is deciphered out of ambiguities without knowing other symbols than the constituting nucleotides. Moreover entropy of the genetic source of information has a maximal value.     

A code within a code: how codons influence mRNA stability

The genetic code was deciphered more than 50 years ago, but we are only now becoming aware of a second, hidden code. It is the concept of “codon optimality” that enters the scene of developmental and homeostatic gene expression, linking translation rates, mRNA stability, and tRNA abundance. Both at the biological and methodological levels, work by Giraldez and colleagues in this issue of The EMBO Journal paves the way for further analyses of such key regulatory mechanisms.     

Towards a splicing code

A combination of experimental and bioinformatics approaches leads Burge and colleagues (Wang et al., 2004 [this issue of Cell]) to a global view of how an RNA segment may be selected or avoided in mature mRNAs due to biased distributions of exonic enhancers and silencers, a process vital for genome evolution, developmental control, and disease onset.     

The GLUT4 code

Despite being one of the first recognized targets of insulin action, the acceleration of glucose transport into muscle and fat tissue remains one of the most enigmatic processes in the insulin action cascade. Glucose transport is accomplished by a shift in the distribution of the insulin-responsive glucose transporter GLUT4 from intracellular compartments to the plasma membrane in the presence of insulin. The complexity in deciphering the molecular blueprint of insulin regulation of glucose transport arises because it represents a convergence of two convoluted biological systems-vesicular transport and signal transduction. Whereas more than 60 molecular players have been implicated in this orchestral performance, it has been difficult to distinguish between mainly passive participants vs. those that are clearly driving the process. The maze-like nature of the endosomal system makes it almost impossible to dissect the anatomical nature of what appears to be a medley of many overlapping and rapidly changing transitions. A major limitation is technology. It is clear that further progress in teasing apart the GLUT4 code will require the development and application of novel and advanced technologies that can discriminate one molecule from another in the living cell and to superimpose this upon a system in which the molecular environment can be carefully manipulated. Many are now taking on this challenge.