Protein arginine methylation in lymphocyte signaling.

Methylation of arginine is an additional option within the repertoire of post-translational modifications that proteins utilize for their communication with other partner proteins and nucleic acids, which ultimately contributes to cellular functions. Recent studies reveal that protein arginine methylation is more common and widespread than previously thought and that it is implicated in a number of key cellular processes including signal transduction. Two recent investigations have propelled this new world of protein modification into the immunological community by showing that TCR and CD28 signaling exploit this pathway.

Arginine methylation of NIP45 modulates cytokine gene expression in effector T lymphocytes.

Posttranslational modification of proteins within T cell receptor signaling cascades allows T lymphocytes to rapidly initiate an appropriate immune response. Here we report a role for arginine methylation in regulating cytokine gene transcription in the T helper lymphocyte. Inhibition of arginine methylation impaired the expression of several cytokine genes, including the signature type 1 and type 2 helper cytokines, interferon gamma, and interleukin-4.

Arginine methylation of RNA helicase a determines its subcellular localization.

RNA helicase A (RHA) undergoes nuclear translocation via a classical import mechanism utilizing karyopherin beta. The nuclear transport domain (NTD) of RHA is known to be necessary and sufficient for its bi-directional nuclear trafficking. We report here that arginine methylation is a novel requirement for NTD-mediated nuclear import.