Tia-1

TIA stands for the acronym "T-cell-restricted intracellular antigen-1", an RNA-binding cytotoxic protein that is a component of stress granules. The TIA protein belongs to the "RNA-binding protein family". It is expressed in cytotoxic T cells, NK cells, but also by skeletal muscle cells. TIA-1 has nucleolytic activities directed against cytotoxic T lymphocytes and is involved in the process of programmed cell death(apoptosis). The TIA1 gene coding for this protein is localized on chromosome 2p13.3.

Stress granules are well-characterized cytoplasmic RNA granules that are formed under certain stress conditions of the cells, e.g. under UV irradiation. The accumulation of granules in the cytoplasm of the cells leads to an arrest of the cells in the G1 phase of the cell cycle. This allows UV-induced DNA damage, for example, to be repaired.

TIA1-positive cells can be found in increased numbers in lymphomatoid papulosis.

1. Moutaoufik MT et al (2014) UVC-induced stress granules in mammalian cells. PLoS One 9:e112742.