GREB1 (gene regulated by estrogen in breast cancer 1) was first identified as an estrogen-regulated gene expressed in breast cancer [1,2]. Its exact function is not known but its expression is regulated by the coordinated binding of estrogen-receptors to distal sites interacting with Pol II to activate gene transcription from core promoters located at a considerable distance from the greb1 gene [2,3,4]. It acts as a regulator of hormone-dependent cancer growth in breast, ovarian and prostate cancers [3,4,5]. This is a presumed domain found adjacent the N-terminal domain of GREB1 and GREB1-like proteins. Structure predictions suggest that it may adopt an alpha/beta fold.

1: GREB 1 is a critical regulator of hormone dependent breast cancer growth. Rae JM, Johnson MD, Scheys JO, Cordero KE, Larios JM, Lippman ME; Breast Cancer Res Treat. 2005;92:141-149. PMID:15986123

2: GREB1 is a novel androgen-regulated gene required for prostate cancer growth. Rae JM, Johnson MD, Cordero KE, Scheys JO, Larios JM, Gottardis MM, Pienta KJ, Lippman ME; Prostate. 2006;66:886-894. PMID:16496412

3: Long-range activation of GREB1 by estrogen receptor via three distal consensus estrogen-responsive elements in breast cancer cells. Sun J, Nawaz Z, Slingerland JM; Mol Endocrinol. 2007;21:2651-2662. PMID:17666587

4: GREB1 is an estrogen receptor-regulated tumour promoter that is frequently expressed in ovarian cancer. Hodgkinson K, Forrest LA, Vuong N, Garson K, Djordjevic B, Vanderhyden BC; Oncogene. 2018;37:5873-5886. PMID:29973689

5: GREB1 amplifies androgen receptor output in human prostate cancer and contributes to antiandrogen resistance. Lee E, Wongvipat J, Choi D, Wang P, Lee YS, Zheng D, Watson PA, Gopalan A, Sawyers CL; Elife. 2019; [Epub ahead of print] PMID:30644358