FIGURE 5-22 (A) Cis-active sites in the hGH promoter. Transcription of the GH-1 gene is regulated by proteins that bind to regulatory elements in the 300 bp preceding the start of transcription (arrow). The two Pit-l-binding sites are shown together with sites for NF-1, USF, AP2, Spl, and the glucocorticoid receptor. (B) Pit-1 protein, helices, and domains. The human Pit-1 gene encodes a 291-amino-acid protein that binds to regulatory elements in the GH, PRL, and Pit-1 promoters. It consists of three recognized domains. They are an amino-terminal transcriptional activation domain, a POU-homeo-specific domain containing two «-helices, and a POU-homeodomain containing three a-helices. Reproduced with permission from Parks, J. S., Pfaffle, R. W., Brown, M. R., Abdul-Latif, H„ and Meacham, L. R. (1995). Growth hormone deficiency. In "Molecular Endocrinology" (B. D. Weintraub, ed.), pp. 473-490. Raven Press, NY.

Transcriptional Activation

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