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Comparative studies on microinjected high-mobility-group chromosomal proteins, HMG1 and HMG2

The nonhistone chromosomal proteins, HMG1 and HMG2, were iodinated and introduced into HeLa cells, bovine fibroblasts, or mouse 3T3 cells by erythrocyte-mediated microinjection. Autoradiographic analysis of injected cells fixed with glutaraldehyde consistently showed both molecules concentrated with...

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Detalles Bibliográficos
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1981
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2111988/
https://www.ncbi.nlm.nih.gov/pubmed/6458621
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description The nonhistone chromosomal proteins, HMG1 and HMG2, were iodinated and introduced into HeLa cells, bovine fibroblasts, or mouse 3T3 cells by erythrocyte-mediated microinjection. Autoradiographic analysis of injected cells fixed with glutaraldehyde consistently showed both molecules concentrated within nuclei. Fixation with methanol, on the other hand, resulted in some leakage of the microinjected proteins from the nuclei so that more autoradiographic grains appeared over the cytoplasm or outside the cells. Both injected and endogenous HMG1 and HMG2 partitioned unexpectedly upon fractionation of bovine fibroblasts, HeLa, or 3T3 cells, appearing in the cytoplasmic fractions. However, in calf thymus, HMG1 and HMG2 molecules appeared in the 0.35 M NaCl extract of isolated nuclei, as expected. These observations show that the binding of HMG1 and HMG2 to chromatin differs among cell types or that other tissue-specific components can influence their binding. Coinjection of [125I]HMG1 and [131I]HMG2 into HeLa cells revealed that the two molecules display virtually equivalent distributions upon cell fractionation, identical stability, identical intracellular distributions, and equal rates of equilibration between nuclei. In addition, HMG1 and HMG2 did not differ in their partitioning upon fractionation nor in their stability in growing vs. nongrowing 3T3 cells. Thus, we have not detected any significant differences in the intracellular behavior of HMG1 and HMG2 after microinjection into human, bovine, or murine cells.
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spelling pubmed-21119882008-05-01 Comparative studies on microinjected high-mobility-group chromosomal proteins, HMG1 and HMG2 J Cell Biol Articles The nonhistone chromosomal proteins, HMG1 and HMG2, were iodinated and introduced into HeLa cells, bovine fibroblasts, or mouse 3T3 cells by erythrocyte-mediated microinjection. Autoradiographic analysis of injected cells fixed with glutaraldehyde consistently showed both molecules concentrated within nuclei. Fixation with methanol, on the other hand, resulted in some leakage of the microinjected proteins from the nuclei so that more autoradiographic grains appeared over the cytoplasm or outside the cells. Both injected and endogenous HMG1 and HMG2 partitioned unexpectedly upon fractionation of bovine fibroblasts, HeLa, or 3T3 cells, appearing in the cytoplasmic fractions. However, in calf thymus, HMG1 and HMG2 molecules appeared in the 0.35 M NaCl extract of isolated nuclei, as expected. These observations show that the binding of HMG1 and HMG2 to chromatin differs among cell types or that other tissue-specific components can influence their binding. Coinjection of [125I]HMG1 and [131I]HMG2 into HeLa cells revealed that the two molecules display virtually equivalent distributions upon cell fractionation, identical stability, identical intracellular distributions, and equal rates of equilibration between nuclei. In addition, HMG1 and HMG2 did not differ in their partitioning upon fractionation nor in their stability in growing vs. nongrowing 3T3 cells. Thus, we have not detected any significant differences in the intracellular behavior of HMG1 and HMG2 after microinjection into human, bovine, or murine cells. The Rockefeller University Press 1981-11-01 /pmc/articles/PMC2111988/ /pubmed/6458621 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Articles
Comparative studies on microinjected high-mobility-group chromosomal proteins, HMG1 and HMG2
title Comparative studies on microinjected high-mobility-group chromosomal proteins, HMG1 and HMG2
title_full Comparative studies on microinjected high-mobility-group chromosomal proteins, HMG1 and HMG2
title_fullStr Comparative studies on microinjected high-mobility-group chromosomal proteins, HMG1 and HMG2
title_full_unstemmed Comparative studies on microinjected high-mobility-group chromosomal proteins, HMG1 and HMG2
title_short Comparative studies on microinjected high-mobility-group chromosomal proteins, HMG1 and HMG2
title_sort comparative studies on microinjected high-mobility-group chromosomal proteins, hmg1 and hmg2
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2111988/
https://www.ncbi.nlm.nih.gov/pubmed/6458621