Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hybridomas were formed between mouse myeloma cells and spleen cells from mice immunized with Marek's disease virus (MDV) or with herpesvirus of turkeys (HVT). Three monoclonal antibodies were obtained, two (M26 and M34) from MDV clones and one (H9) from an HVT clone, all of which were specific for cross-reactive membrane antigen (MA) expressed on the surface of cells infected with MDV or HVT. All three antibodies also reacted with MDV- and HVT-specific glycoproteins in the molecular weight (mol. wt.) ranges 54K to 70K (MDV-gp54/70) and 50K to 64K (HVT-gp50/64), respectively. These glycoproteins constitute the putative 'A' antigens which are found in the medium of cultures infected with MDV or HVT. These results suggest that the cross-reactive MA may correspond to 'A' antigen. Pulse-chase experiments using monoclonal antibodies revealed the presence in virus-infected cells of precursor and processed forms of MDV-gp54/70 and HVT-gp50/64 which differ in size. Moreover, by two-dimensional gel electrophoresis we found that MDV and HVT glycoproteins were separated to heterogeneous spots by electric charge as well as mol. wt. The several spots with higher mol. wt. and with more acidic isoelectric points among them were lost by treatment with neuraminidase, suggesting that the processing was, at least in part, due to the addition of sialic acid to the precursor forms. Tunicamycin blocked the surface expression of cross-reactive HVT-MA on HVT-infected cells. Phosphonoacetic acid inhibited both the appearance of HVT-MA on the cell surface and synthesis of HVT-gp50/64, indicating that the MA and secreted glycoprotein were late gene products of the HVT genome.
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PMID:Monoclonal antibodies reactive with the surface and secreted glycoproteins of Marek's disease virus and herpesvirus of turkeys. 619 39

Analysis of nascent heavy chains isolated from MPC11 (gamma 2b heavy chains) and MOPC 21 (gamma 1 heavy chains) mouse myeloma cells demonstrates an accumulation of nascent heavy chains which are slightly smaller in mass (approximately 35,000 daltons) than nascent heavy chains which have just been glycosylated (approximately 38,000 daltons). The accumulation of 35,000-dalton nascent heavy chain appears to be a consequence of the glycosylation process since tunicamycin, an inhibitor of glycosylation, abolishes the apparent translational block manifested by the accumulation of 35,000-dalton nascent chains. Tunicamycin also causes a 15 to 25% increase n the relative rate of synthesis of heavy chain compared to the corresponding rate of synthesis of the nonglycosylated light chain synthesized by the same cell. These results suggest that the translation block, caused by the glycosylation process, of heavy chain synthesis contributes to the imbalance of heavy chain and light chain biosynthesis observed in malignant and normal lymphoid cells.
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PMID:Glycosylation causes an apparent block in translation of immunoglobulin heavy chain. 677 72

Previous reports, using a variety of myeloma cell lines and activated normal B cells, have shown that different classes of immunoglobulins have different carbohydrate requirements for secretion. Thus, secretion of IgM and IgE was almost totally blocked by the antibiotic tunicamycin, secretion of IgA was partially inhibited, and secretion of IgG was essentially unaffected (Hickman, S., Kulczycki, A., Jr., Lynch, R. G., and Kornfeld, S. (1977) J. Biol. Chem. 252, 4402-4408; Hickman S., (1978) J. Immunol. 121, 990-996). Here, similar experiments using hybridoma cell lines secreting IgM and IgG or IgD are reported. Tunicamycin prevented the majority of IgM secretion but did not affect IgG secretion in cells producing both isotypes. This shows that the differential effects of tunicamycin on IgM and IgG secretion are due to factors intrinsic to the respective heavy chain polypeptides themselves, rather than to other properties of the producing cells. The secretion of IgD, which is as heavily glycosylated as IgM, was not inhibited by tunicamycin. Thus, the simple degree of immunoglobulin heavy chain glycosylation does not determine the extent of the requirement for glycosylation in the secretion of that isotype.
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PMID:Differing requirements for glycosylation in the secretion of related glycoproteins is determined neither by the producing cell nor by the relative number of oligosaccharide units. 679 68