SCL-interrupting locus protein; TAL-1-interrupting locus protein (STIL SIL)

Function

• immediate-early gene protein
• role in embryonic development, cellular growth & proliferation
• its long-term silencing affects cell survival & cell cycle distribution as well as decreases CDC2 activity correlated with reduced phosphorylation of CDC2.
• role as a positive regulator of the sonic hedgehog pathway, acting downstream of PTCH1
• interacts with PIN1 via its WW domain, dependent on STIL mitotic phosphorylation (putative)
• phosphorylated following the activation of the mitotic checkpoint

Compartment

cytoplasm, cytosol

Alternative splicing

named isoforms=2

Expression

• expressed in all hematopoietic tissues & cell lines
• down-regulated when cell proliferation ceases
• accumulates during G2 phase & falls at completion of the cell cycle

Pathology

• highly expressed in a variety of tumors characterized by increased mitotic activity with highest expression in lung cancer
• chromosomal deletion at 1p32 between STIL & TAL1 genes leads to STIL/TAL1 fusion mRNA with STIL exon 1 slicing to TAL1 exon 3 in some T-cell acute lymphoblastic leukemias (T-ALL)
• fusion protein with SCL protein seen in 1;14 translocations of hematopoietic stem cell leukemias

More general terms

• phosphoprotein

Database

• UniProt: http://www.uniprot.org/uniprot/Q15468.html