EF-1-beta and EF-1-delta stimulate the exchange of GDP bound to EF-1-alpha to GTP, regenerating EF-1-alpha for another round of transfer of aminoacyl-tRNAs to the ribosome. Regulates induction of heat-shock-responsive genes through association with heat shock transcription factors and direct DNA-binding at heat shock promoter elements (HSE). EF-1 is composed of 4 subunits: alpha, beta, delta isoform 1, and gamma. Isoform 2 interacts with HSF1 and NFE2L2. Isoform 2 is specifically expressed in brain, cerebellum and testis. By homocysteine (HC), may mediate accelerated synthesis of free thiol-containing proteins in response to HC-induced oxidative stress. Also induced following exposure to ionizing radiation. Belongs to the EF-1-beta/EF-1-delta family.