It is a member of the 14-3-3 family which consists of 30 kDa proteins that are involved in multiple cell signalling pathways, regulation of cell cycle progression, cytoskeletal structure, transcription, intracellular trafficking and targeting. Protein interactions with 14-3-3 show distinct preferences for it’s different isoforms and are regulated by phosphorylation of both 14-3-3 and the bound protein. 14-3-3 tau/theta is primarily expressed in T-cells although it occurs at lower levels in the brain, heart, pancreas placenta and kidneys. It plays a role in cell cycle progression via interaction with p27(Kip1). Along with COPI, the theta isoform binds the GB1 RSR sequence involved in protein trafficking. The isoform forms a complex with Hsp60 and cellular prion protein which may be involved in prion diseases. Elevated levels of 14-3-3 tau/theta are observed in amyotrophic lateral sclerosis. 14-3-3 tau/theta also binds BCR/Abl, bacterial effector protein Tir, yes-associated protein and the FSH receptor.