POMC gene

The POMC gene is expressed in the anterior and intermediate lobes of the pituitary. The most conserved sequences between species are within the amino terminal fragment, the ACTH region, and the (3-endorphin region. POMC or related products are found in several other vertebrate tissues, including the brain, placenta, gastrointestinal tract, reproductive tract, lung, and lymphocytes. 

As a result of transcription of the POMC gene and maturation of the hnRNA, a mature mRNA consisting of some 1100 nucleotides... 

Crowe RR, Noyes R Jr, Persico AM (1987a) Pro-opiomelanocortin (POMC) gene excluded as a cause of panic disorder in a large family. J Affect Disord 12 23-27 Crowe RR, Noyes R Jr, Wilson AF, Elston RC, Ward LJ (1987b) A linkage study of panic disorder. Arch Gen Psychiatry 44 933-937... 

Hinney, A., Becker, I., Heibult, O., Nottebom, K., Schmidt, A., Ziegler, A., Mayer, H., Siegfried, W, Blum, W.F., Remschmidt, H., Hebebrand, J. (1998) Systematic mutation screening of the POMC gene. J Clin Endocrinol and Metab 83 3737-3741. 

In some cases, prohormone proteins yield a single peptide hormone, but often several active hormones are carved out of the same prohormone. Pro-opiomelano-cortin (POMC) is a spectacular example of multiple hormones encoded by a single gene. The POMC gene encodes a large polypeptide that is progressively carved up into at least nine biologically active peptides (Fig. 23-6). The terminal residues of peptide hormones are often modified, as in TRH (Fig. 23-2). 

CRH ACTH and other hormones from the POMC gene Adrenal Cortisol Response to stress... 

The protein product of the proopiomelanocortin (POMC) gene may be cleaved to generate a number of polypeptides. 

B) Vasopressin (C) Both oxytocin and vasopressin (D) Neither oxytocin nor vasopressin (POMC) gene... 

D. The POMC gene produces a protein that is cleaved to form ACTH, lipotropin, MSH, and endorphins. 

Opioids increase appetite and stimulate food intake, whereas opiate antagonists inhibit food intake in food-deprived animals. Although circulating levels of /1-endorphin were found to be higher in obese than in lean women, there is no evidence that obesity is caused by an imbalance in endorphin production. However, a relationship between early-onset obesity and inherited defects in the POMC gene that leads to a lack of production of ACTH, MSH (a, p, y), and 6-endorphin has been observed in humans (discussed later). 

The proopiomelanocortin (POMC) gene encodes several regulatory proteins that affect pituitary function. In different brain regions, proteins encoded by this gene have different carboxy-terminal peptides. Which of the following best explains the regulatory mechanism ... 

Chronic administration of THC increased corticotropin-releasing hormone (CRH) and proopiomelanocortin (POMC) gene expression in the rathypothalamus (Corchero et al. 2001). Circulating gonadal steroids facilitate the latter effect. 

P rez-Rosado A, Gomez M, Manzanares J, Ramos JA, Fernandez-Ruiz J (2002) Changes in prodynorphine and POMC gene expression in several brain regions of rat fetuses prenataUy exposed to A -tetrahydrocannabinol. Neurotox Res 4 211-218... 

ACTH is derived from a large polypeptide precursor, proopiomelanocortin (POMC) that also includes in its amino acid sequence both MSH and the related opiate -lipotropin (y3-LPH), the latter giving rise to the biologically active )3-endorphin (Mains and Eipper, 1980). POMC, a 31 kDa polypeptide, is synthesized in the anterior and intermediate lobes of the pituitary gland, which is the most important source of this prohormone. Other notable sources of POMC synthesis in the brain include the amygdala and the arcuate nucleus of the hypothalamus (Watson and Akil, 1980 Civelli et al., 1982). In addition, the structure of the POMC molecule, the POMC gene and the mRNA sequence for POMC have been elucidated (Roberts... 

Frog POMC gene expres- Direct peptide se- Micro scale extrac- 51,... 

Teofali, R, Motoki, K., Lotti, T.M., Uitto, J., and Mauviel, A. (1997) Propiomelanocortin (POMC) Gene Expression by Normal Skin and Keloid Fibroblasts in Culture Modulation by Cytokines, Exp. Dermatol. 6,111-115. 

Getting, S.J., Gibbs, L, Clark, A.J., Flower, R.J., and Perretti, M. (1999) POMC gene-derived peptides activate melanocortin type 3 receptor on murine macrophages, suppress cytokine release, and inhibit neutrophil migration in acute experimental inflammation, fourrud of Immunology (Baltimore, Md 1950), 162, 7446-7453. 

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