Members of this family of proteins act as negative regulators of G1 to S cell cycle phase progression by inhibiting cyclin-dependent kinases. Inhibitory effects are additive with GADD45 proteins but occur also in the absence of GADD45 proteins. Furthermore, they act as a repressor of the orphan nuclear receptor NR4A1 by inhibiting AB domain-mediated transcriptional activity []. They may be involved in the hormone-mediated regulation of NR4A1 transcriptional activity.
This superfamily represents a domain found in proteins which act as negative regulators of G1 to S cell cycle phase progression by inhibiting cyclin-dependent kinases. Inhibitory effects are additive with GADD45 proteins but occur also in the absence of GADD45 proteins. Furthermore, they act as a repressor of the orphan nuclear receptor NR4A1 by inhibiting AB domain-mediated transcriptional activity []. They may be involved in the hormone-mediated regulation of NR4A1 transcriptional activity.Structurally, this domain consists of 4 alpha helices.
