Securin sister-chromatid separation inhibitor (IPR006940)

Short name: Securin_separation_inhibitor

Overlapping homologous superfamilies


Family relationships



Securin, also known as pituitary tumour-transforming gene product is a regulatory protein which plays a central role in chromosome stability in the p53/TP53 pathway, and in DNA repair. It probably acts by blocking the action of key proteins, for example, during 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, leading to its destruction and to the liberation of ESPL1. Its function is however not limited to an inhibitory activity, since it is required to activate ESPL1. The negative regulation of the transcriptional activity and related apoptosis activity of TP53 may explain the strong transforming capability of the protein when it is overexpressed. Over-expression of securin is associated with a number of tumours, and it has been proposed that this may be due to erroneous chromatid separation leading to chromosome gain or loss [PMID: 10411507].

GO terms

Biological Process

GO:0051276 chromosome organization

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0005737 cytoplasm
GO:0005634 nucleus

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.