Translation elongation

The synthesis of proteins in eukaryotes is typically divided into four steps, i.e. initiation, elongation, termination and ribosome recycling. This key biological event is tightly regulated by the cell. Under conditions of increased demand or reduced production of cellular energy the cell can downregulate this process. While a tight regulation exists for the rate-limiting initiation step, elongation also appears to be under somewhat strict control. Among key targets of elongation regulation are the eukaryotic elongation factors A1/A2 (eEF1A1/A2) and the eukaryotic elongation factor 2 (eEF2). In addition to being involved in the regulation of protein synthesis, evidence indicates that these factors play a relevant role in the genesis and maintenance of many forms of human cancers. For this reason, elongation factors have been considered as valuable markers for different forms of cancers, as well as attractive candidates for targeted anticancer therapeutic approaches. In this chapter we focus on the description of the factors taking part in the process of elongation, as well as their involvement in cancer. Particular emphasis is put on the description of (1) the physiological role of elongation factors in elongation and in other biological processes; (2) the control of elongation factors by signaling pathways; (3) the involvement of elongation factors in cancer and (4) the anticancer therapeutic approaches based on the targeting of elongation factors