Neuroendocrine cell type-specific and inducible expression of the secretogranin II gene: crucial role of cyclic adenosine monophosphate and serum response …

SK Mahata, M Mahata, CV Livsey, HH Gerdes… - …, 1999 - academic.oup.com
SK Mahata, M Mahata, CV Livsey, HH Gerdes, WB Huttner, DT O'Connor
Endocrinology, 1999academic.oup.com
Secretogranin II, an acidic protein in the chromogranin/secretogranin family, is widely
distributed in neuroendocrine secretory granules. What factors govern such widespread, yet
selective, expression? The 5′ deletions localized neuroendocrine cell type-specific
expression to the proximal mouse secretogranin II promoter: such expression was abolished
after deletion past the cAMP response element (CRE;[− 67 bp] TGACGTCA [− 60 bp]), and
transfer of the CRE to a neutral promoter conferred 3.4-to 5.3-fold neuroendocrine …
Abstract
Secretogranin II, an acidic protein in the chromogranin/secretogranin family, is widely distributed in neuroendocrine secretory granules. What factors govern such widespread, yet selective, expression? The 5′ deletions localized neuroendocrine cell type-specific expression to the proximal mouse secretogranin II promoter: such expression was abolished after deletion past the cAMP response element (CRE; [−67 bp]TGACGTCA[−60 bp]), and transfer of the CRE to a neutral promoter conferred 3.4- to 5.3-fold neuroendocrine selectivity. Thus, the CRE is, at least partly, sufficient to confer tissue-specific expression. Substantial (48–59%) loss of cell type-specific expression also occurred upon deletion past the serum response element (SRE; [−302 bp]GATGTCC[−296 bp]), and transfer of the SRE to a neutral promoter also conferred neuroendocrine selectivity. Expression of both the endogenous gene and the transfected secretogranin II promoter was up-regulated after secretagogues, and the degree of trans-activation of the transfected promoter (2.2- to 5.4-fold) paralleled activation of the endogenous gene (1.8- to 3.2-fold). The 5′ promoter deletions revealed complete loss of secretagogue responses after deletion past the CRE. Transfer of the CRE to a neutral promoter conferred secretagogue responses (by 2.2- to 18.6-fold). Substantial (59–74%) falls in secretagogue responses also occurred after deletion past the promoter’s SRE. Transfer of the SRE to a neutral promoter conferred secretagogue responses (by 2.7- to 8.3-fold). We conclude that the CRE is a crucial determinant of cell type-specific constitutive and secretagogue-inducible expression of the secretogranin II gene and that the SRE also plays a substantial role in both processes.
Oxford University Press