COUP-TF (chicken ovalbumin upstream promoter transcription factor)-interacting protein 1 (CTIP1) is a sequence-specific DNA binding protein

• Published in: Biochemical journal Vol. 368; no. Pt 2; pp. 555 - 563
• Main Authors: Avram, Dorina, Fields, Andrew, Senawong, Thanaset, Topark-Ngarm, Acharawan, Leid, Mark
• Format: Journal Article
• Language: English
• Published: England 01.12.2002
• Subjects: Animals; Base Sequence; Binding Sites; Carrier Proteins - drug effects; Carrier Proteins - genetics; Carrier Proteins - metabolism; Cells, Cultured; Conserved Sequence; DNA-Binding Proteins - drug effects; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Humans; Hydroxamic Acids - pharmacology; Mammals; Nuclear Proteins - drug effects; Nuclear Proteins - genetics; Nuclear Proteins - metabolism; Promoter Regions, Genetic; Repressor Proteins - drug effects; Repressor Proteins - genetics; Repressor Proteins - metabolism; Response Elements; Solutions; Substrate Specificity; Transcription, Genetic; Zinc Fingers
• ISSN: 0264-6021; 1470-8728
• DOI: 10.1042/bj20020496

Chicken ovalbumin upstream promoter transcription factor (COUP-TF)-interacting proteins 1 and 2 [CTIP1/Evi9/B cell leukaemia (Bcl) l1a and CTIP2/Bcl11b respectively] are highly related C(2)H(2) zinc finger proteins that are abundantly expressed in brain and the immune system, and are associated with immune system malignancies. A selection procedure was employed to isolate high-affinity DNA binding sites for CTIP1. The core binding site on DNA identified in these studies, 5'-GGCCGG-3' (upper strand), is highly related to the canonical GC box and was bound by a CTIP1 oligomeric complex(es) in vitro. Furthermore, both CTIP1 and CTIP2 repressed transcription of a reporter gene harbouring a multimerized CTIP binding site, and this repression was neither reversed by trichostatin A (an inhibitor of known class I and II histone deacetylases) nor stimulated by co-transfection of a COUP-TF family member. These results demonstrate that CTIP1 is a sequence-specific DNA binding protein and a bona fide transcriptional repressor that is capable of functioning independently of COUP-TF family members. These findings may be relevant to the physiological and/or pathological action(s) of CTIPs in cells that do not express COUP-TF family members, such as cells of the haematopoietic and immune systems.