???????????? ?????????? ?? ?????????????????? ?????????????????????????? ???????????????????? ?? ???????? ???????????????????? ??????????????. ?????? ???????????????????? ?????????????? ???????????? ?????? ???????????????? ???????????????????? ?????????????????????????????? ???????????????????? ???????????? ?? ???????? ???? ????????. ???????????????? ???? ?????????????? ???????????????????????????????? ???????????????? ?? ?????????????????????????? ??????????????, ?????????????? ???? ?????????????????????????? ?? ?????????????????????????? ?????????????? ?? ?????????????????????? ?????????????? ???????????????? ?????????? ????????????????????????. ?? ?????????????????? ?????????? ?? ???????????????? ???????????????? ???????????????????????????? ?????????????????????????? ???? ?????????????????????????????? ??????????????????, ?? ???? ?????????? ?????? ?????????????????????? ???????????????? ???????????????? ?????????? ?????????????????? ???????????????????????? ???????? ?? ???????????? ?????????????????? ??????????????????. ?? ???????????? ???????????????????? ?????????????? ???????????? ?????????????????????????? ?????????????? ?????????????? ???????????? ?? ???????? ???? ??????????, ???????????????????? ?????????????? ????????????. ???????????????????????? ???????????? ?????????????????????????? ?????????? ???????????????????????????? ?????????????? ???????????????????????????????????? ???????????????? ?????????????? ?????????????????????? ???? ?????????????? ?????????????????? ???????????????????? ?? ???????????????? ?????????????? ?????????????? ?????????????????? ???????????????????? 1A (eEF1A).

???????????? ?????????????????? ???????????? ?? ?????????????????? ?????????????? ?????????? ?? ?????????????? ?????????????????? ??????????????. ???? ???????????????? ?????????????????? ?????????????? ????????-???? ?????? ?? ?????????????????????????? ?????????????????????????? ?????????????????? ???????? ?? ???????????? ????????. ???????????????????? ???? ?????????????? ???????????????????????????????? ?????????????? ?? ?????????????????????????? ??????????????, ?????????????? ?????????????? ?????????????????? ???? ???????????????????? ?????????????? ?? ?????????????????? ???????????????? ?????????????????????? ???????????????????? ????????????????????. ???????????????? ?????????? ?????????? ?????????????????????? ?????????????????????? ?????????????????????? ???? ???????????????????????? ??????????????????, ?? ?????? ?????? ???? ???????????????????? ?????????????? ???????????????? ???????????? ?????????????????????? ?????????????? ???????? ?? ???????????? ?????????????????? ????????????????. ?? ???????????? ???????????????????? ???????????????? ???????????? ?????????????????????? ?????????????? ?????????????? ???????? ?? ???????????? ??????????, ?????? ?????????????????? ?????????????? ????????????. ?????????????????????? ??????????????????, ???? ???????? ?????????????????????????? ?????????????????? ?????????? ?????????????? ?????????????? ?? ???????????????????????????????????? ???????????????? ?????????????? ?????????????????????????? ???? ???????????????? ???????????????? ?????????????????? ?? ???????????????? ?????????????? ?????????????? ?????????????????? ???????????????????? 1A (eEF1A).

Many proteins in mammalian organism exist as isoforms. These isoforms can be encoded by different genes or produced by alternative splicing of one gene. Despite rapid instrumental progress in the isoform identification, the reasons for their existence and specific functions remain largely unknown. During recent years, attention of researchers was mostly concentrated on spliced isoforms, while the variants of the same protein coded by different genes can play an essential role in different cell processes. This review presents examples of different potential functions of the protein isoforms coded by different genes. Molecular background which could provide a difference between highly homologous protein variants is discussed with an example of isoforms translation elongation factor 1A (eEF1A).