Posttranscriptional regulation of mRNAs important in T cell function.

Publisher Summary This chapter discusses how post-transcriptional gene regulation, especially alterations in mRNA stability, contributes to the ultimate phenotype of a T lymphocyte. It also deals with the measurement of mRNA decay rates within cells. The rate of mRNA decay is equal to the production rate (transcription) minus net accumulation. All the methods for the measurement of mRNA decay must quench ongoing transcription or mask its presence. Some of these methods include—pulse chase, transcriptional blockade, and a variety of inducible promoter systems. The ability to rapidly modulate cytoplasmic mRNA quantity and translatability is critical for T lymphocytes to effectively respond to environmental change. A large number of T lymphocyte and other cell mRNAs are dominantly controlled by alterations in their stability and/or translatability rather than by transcriptional control. A large and growing number of human genes are regulated at the level of mRNA stability. This pathway can rapidly and effectively increase or decrease the levels of coding mRNA, modulating gene expression as needed. The underlying mechanism for these effects relies on cis-trans interactions that identify and target particular mRNAs. A large number of important mRNAs are regulated in this way, including cytokines, protooncogenes, and cell surface receptors.