Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The homogeneous nature of the rat intermediate pituitary makes it a powerful model system in which to study peptide hormone secretion. Adult male rats were treated with bromocriptine, a dopamine agonist, or haloperidol, a dopamine antagonist, for 3 weeks. In cDNA libraries prepared from the neurointermediate pituitaries of these rats, pro-opiomelanocortin (POMC) expression exhibited the expected decrease in response to bromocriptine, and increase in response to haloperidol. We report the identification of six transcripts that are coregulated with POMC in the intermediate pituitary by these dopaminergic agents. In addition to demonstrating parallel dopamine-regulated expression of carboxy-peptidase E, chromogranin B, binding protein/glucose-regulated protein, and tenascin, two novel regulated transcripts are described. The expression of one of these novel transcripts, RESP18, is limited to neural and endocrine tissue. The RESP18 transcript is approximately 800 nucleotides in length; its cognate translation product is 20 +/- 1 kDa, contains a putative signal sequence, and has many characteristics of a secreted protein. Cell-free translation experiments in the presence of microsomal membranes demonstrate that the 20 +/- 1-kDa RESP18 protein is cleaved to an 18 +/- 1-kDa protein and sequestered within the lumen of the rough endoplasmic reticulum. Tissue in situ hybridization analysis shows that RESP18 mRNA is highly expressed in both the intermediate and anterior pituitary, as well as in the paraventricular and supraoptic nuclei of the hypothalamus.
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PMID:RESP18, a novel endocrine secretory protein transcript, and four other transcripts are regulated in parallel with pro-opiomelanocortin in melanotropes. 813 49

RESP18 (regulated endocrine-specific protein of 18 KD) is an endoplasmic reticulum (ER) protein that was identified by coordinate dopaminergic regulation with pro-opiomelanocortin in the rat neurointermediate pituitary. Many attributes of RESP18 suggest an important function in neuroendocrine cells. Several neuropeptides, growth factors, and enzymes involved in biosynthesis of classical chemical neurotransmitters, have been identified in germ cells, Sertoli cells, and spermatozoa. In this study, screening of reproductive tissues revealed high levels of RESP18 protein and mRNA in the testes but not in ovaries or epididymis. The testes and sperm expressed 18-KD RESP18 and a unique 19-KD isoform. To better understand RESP18 expression in the testes, we have examined the stages of the cycle of the seminiferous epithelium by immunohistochemistry and Western blot analyses. Immunohistochemical analysis showed that RESP18 protein was expressed exclusively in spermatocytes and maturing spermatids. RESP18 protein was expressed at high levels in Step 1-8 round spermatids, in which the PC4 prohormone convertase, nerve growth factor, and proenkephalin are also expressed. Western blots, Northern blots, and indirect immunofluorescence staining demonstrated RESP18 expression in sperm.
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PMID:Stage-specific expression of RESP18 in the testes. 898 41