Component of the elongator complex which is required for multiple tRNA modifications, including mcm5U (5-methoxycarbonylmethyl uridine), mcm5s2U (5-methoxycarbonylmethyl-2-thiouridine), and ncm5U (5-carbamoylmethyl uridine) (By similarity). The elongator complex catalyzes the formation of carboxymethyluridine in the wobble base at position 34 in tRNAs (PubMed:23717213). Regulates the migration and branching of projection neurons in the developing cerebral cortex, through a process depending on alpha-tubulin acetylation (PubMed:22854966). ELP1 binds to tRNA, mediating interaction of the elongator complex with tRNA (By similarity). May act as a scaffold protein that assembles active IKK-MAP3K14 complexes (IKKA, IKKB and MAP3K14/NIK) (By similarity). tRNA modification; 5-methoxycarbonylmethyl-2-thiouridine-tRNA biosynthesis. Homodimer; dimerization promotes ELP1 stability and elongator complex formation. Component of the elongator complex which consists of ELP1, ELP2, ELP3, ELP4, ELP5 and ELP6. Interacts preferentially with MAP3K14/NIK followed by IKK-alpha and IKK-beta. In the testis, expression is restricted to germ cells during spermatogenesis with no expression detected in somatic cells such as Sertoli cells or Leydig cells (at protein level) (PubMed:23717213). In the ovary, expressed in oocytes of primary, secondary and antral follicles (at protein level) (PubMed:31827135). Widely expressed in adult tissues with highest levels in brain and also expressed at all embryonic stages (PubMed:11747609). During spermatogenesis, expressed in the testis in all male germ cell stages except elongated spermatids (at protein level) (PubMed:23717213). Highly expressed in fully-grown germinal vesicle oocytes and modest expression throughout the preimplantation stage with a slight down-regulation at the 2-cell stage (PubMed:31827135). In the embryo, expressed at embryonic days 7, 11, 15 and 17 with the highest expression at embryonic day 11 (PubMed:11747609). Phosphorylated. Conditional knockout in male germ cells results in defects in wobble uridine tRNA modification and defects in synapsis and meiotic recombination which result in increased apoptosis and complete arrest of gametogenesis, leading to male infertility (PubMed:23717213). Conditional knockout in female germ cells results in female subfertility with reduced litter size although ovaries are morphologically and histologically indistinguishable from those of controls (PubMed:31827135). Oocytes show aneuploidy, reduced alpha-tubulin acetylation and are unable to complete meiosis with defects in meiotic spindle organization, chromosome alignment and kinetochore function (PubMed:31827135). Embryos derived from Elp1-deficient oocytes exhibit digyny, progressive delays in preimplantation development and severe degeneration before reaching the blastocyst stage (PubMed:31827135). Belongs to the ELP1/IKA1 family. The elongator complex was originally thought to play a role in transcription elongation. However, it is no longer thought to play a direct role in this process and its primary function is thought to be in tRNA modification.