Securin (Esp1-associated protein) (Pituitary tumor-transforming gene 1 protein) (Tumor-transforming protein 1) (hPTTG)
1_MATLI 6_ YVDKE 11_ NGEPG 16_ TRVVA 21_ KDGLK 26_ LGSGP 31_ SIKAL 36_ DGRSQ 41_ VSTPR 46_ FGKTF 51_ DAPPA 56_ LPKAT 61_ RKALG 66_ TVNRA 71_ TEKSV 76_ KTKGP 81_ LKQKQ 86_ PSFSA 91_ KKMTE 96_ KTVKA 101_ KSSVP 106_ ASDDA 111_ YPEIE 116_ KFFPF 121_ NPLDF 126_ ESFDL 131_ PEEHQ 136_ IAHLP 141_ LSGVP 146_ LMILD 151_ EEREL 156_ EKLFQ 161_ LGPPS 166_ PVKMP 171_ SPPWE 176_ SNLLQ 181_ SPSSI 186_ LSTLD 191_ VELPP 196_VCCDI
1: Regulatory protein, which plays a central role in chromosome stability, in the p53/TP53 pathway, and DNA repair. Probably acts by blocking the action of key proteins. During the mitosis, it blocks Separase/ESPL1 function, preventing the proteolysis of the cohesin complex and the subsequent segregation of the chromosomes. At the onset of anaphase, it is ubiquitinated, conducting to its destruction and to the liberation of ESPL1. Its function is however not limited to a blocking activity, since it is required to activate ESPL1. Negatively regulates the transcriptional activity and related apoptosis activity of TP53. The negative regulation of TP53 may explain the strong transforming capability of the protein when it is overexpressed. May also play a role in DNA repair via its interaction with Ku, possibly by connecting DNA damage-response pathways with sister chromatid separation