How HIV-1 Integrase Associates with Human Mitochondrial Lysyl-tRNA Synthetase

The C-Terminal Domain of HIV-1 Integrase: A Swiss Army Knife for the Virus?

Retroviral integrase is a multimeric enzyme that catalyzes the integration of reverse-transcribed viral DNA into the cellular genome. Beyond integration, the Human immunodeficiency virus type 1 (HIV-1) integrase is also involved in many other steps of the viral life cycle, such as reverse transcription, nuclear import, virion morphogenesis and proviral transcription. All these additional functions seem to depend on the action of the integrase C-terminal domain (CTD) that works as a molecular hub, interacting with many different viral and cellular partners. In this review, we discuss structural issues concerning the CTD, with particular attention paid to its interaction with nucleic acids. We also provide a detailed map of post-translational modifications and interaction with molecular partners.

Hijacking tRNAs From Translation: Regulatory Functions of tRNAs in Mammalian Cell Physiology

Transfer tRNAs (tRNAs) are small non-coding RNAs that are highly conserved in all kingdoms of life. Originally discovered as the molecules that deliver amino acids to the growing polypeptide chain during protein synthesis, tRNAs have been believed for a long time to play exclusive role in translation. However, recent studies have identified key roles for tRNAs and tRNA-derived small RNAs in multiple other processes, including regulation of transcription and translation, posttranslational modifications, stress response, and disease. These emerging roles suggest that tRNAs may be central players in the complex machinery of biological regulatory pathways. Here we overview these non-canonical roles of tRNA in normal physiology and disease, focusing largely on eukaryotic and mammalian systems.