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)

We have found that preparations of rate-zonal purified Moloney murine leukemia virus originally obtained from the National Cancer Institute Resources Program, when separated by SDS-PAGE in the absence of mercaptoethanol (beta-MSH), exhibited a doublet envelope glycoprotein band of approximately 69/67 kD. When the same samples were run in the presence of beta-MSH, a single band at 70 kD (gp70) was observed. Western blot analysis with polyclonal antiserum identified both the 69- and 67-kD bands as envelope gene products. Tryptic peptide mapping of each of the gp67 and gp69 bands confirmed the serological data, with each showing conserved as well as unique peptides. These results imply that the Moloney murine leukemia virus samples examined above contain two structurally different envelope gene products. Western blot analysis using ecotropic and dualtropic specific sera suggest that gp69 is derived from an ecotropic virus, while gp67 is from a dualtropic virus. This is consistent with the results of an earlier study which showed that the majority of the cysteines (4/5) in dualtropic gp70 are lost by a single deletion relative to the ecotropic gp70 species. This would account for the difference in mobility observed in the SDS-PAGE profile in the absence of beta-MSH. It would indicate that the cysteines play an important role in defining structural differences that separate the ecotropic and dualtropic gp70s.
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PMID:Reduction-modifiable properties of Moloney murine leukemia virus gp70 as an indicator of envelope glycoprotein heterogeneity. 252 96

AtT20 cells, a line of murine pituitary tumour cells that secrete adrenocorticotropic hormone (ACTH), have been infected with the coronavirus mouse hepatitis virus strain A59 (MHV-A59). Between 5% and 10% of AtT20 cells are susceptible to the infection. Unlike infections of fibroblastic sac- and 17Cl 1 cells, the infection of AtT20 cells does not lead to cell fusion, despite the production of the fusogenic E2 viral spike glycoprotein. Within infected AtT20 cells the second viral envelope glycoprotein, E1, is located in a perinuclear region; at least until very late in the infection it fails to accumulate to detectable levels in the rough endoplasmic reticulum (RER). By contrast to infection of sac- and 17Cl 1 cells, where the RER is a major site of assembly of progeny virions, in AtT20 cells budding of progeny virions is restricted to the Golgi cisternae, which eventually vesiculate, and peri-Golgi smooth membraned vesicles. Apparently, therefore, the intracellular compartments into which wild-type MHV-A59 buds are determined not by the virus but by the host cells. MHV-A59 infected cultures of AtT20 cells can be serially passaged without loss of the infection or increase in the proportion of infected cells; they become persistently infected carrier cultures. The progeny virus from serially passaged, infected AtT20 cells is apparently wild-type. It infects sac- cells and induces them to form syncitia. Within the sac- syncitia the viral E1 glycoprotein accumulates in the RER and many virions assemble there.
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PMID:Infection of AtT20 murine pituitary tumour cells by mouse hepatitis virus strain A59: virus budding is restricted to the Golgi region. 299 76

The pituitary cell line, AtT-20, synthesizes adrenocorticotropic hormone (ACTH) as a glycoprotein precursor that is cleaved into mature hormones during packaging into secretory granules. The cells also produce an endogenous leukemia virus (MuLV) that is glycosylated after translation similar to the glycosylation of the ACTH precursor. Our evidence suggests that the envelope glycoprotein and some precursor ACTH get to the cell surface in a vesicle different from the mature ACTH secretory granule. Viral glycoproteins and ACTH precursor are released from the cells much sooner after synthesis than mature ACTH. Isolated secretory granules do not contain significant amounts of the envelope glycoprotein or ACTH precursor. Exposing cells to 8Br-cAMP stimulates release of mature ACTH four to five fold, but has little effect on the release of the ACTH precursor or the viral glycoproteins. We propose that the viral glycoproteins and some of the ACTH precursor are transported by a constitutive pathway, while mature ACTH is stored in secretory granules where its release is enhanced by stimulation.
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PMID:Two distinct intracellular pathways transport secretory and membrane glycoproteins to the surface of pituitary tumor cells. 627 13

Melanocortins are proopiomelanocortin-derived peptides that include adrenocorticotropic hormone [ACTH (1-39)], alpha-melanocyte-stimulating hormone [alpha-MSH (1-13)], and related amino acid sequences. Melanocortin peptides have potent antiinflammatory/anticytokine activity. Because cytokines such as interleukin 1 (IL-1) and tumor necrosis factor (TNF) can be detrimental in HIV-infected patients, we investigated the effects of melanocortins on production of IL-1 and TNF alpha in the blood of HIV patients. Cytokine production was measured in whole blood samples stimulated with LPS in the presence or absence of alpha-MSH (1-13), alpha-MSH (11-13), ACTH (1-24), or ACTH (1-39). Melanocortins reduced production of both cytokines in a concentration-dependent fashion. In separate experiments on normal peripheral blood mononuclear cells (PBMC), alpha-MSH (1-13) inhibited production of IL-1 beta and TNF alpha induced by HIV envelope glycoprotein gp 120. These results suggest that stimulation of melanocortin receptors in inflammatory cells could be a novel way to reduce production of cytokines that promote HIV replication.
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PMID:Melanocortin peptides inhibit production of proinflammatory cytokines in blood of HIV-infected patients. 970 Jul 61