TY - JOUR
T1 - Differential inhibition of transcription of DNA by melanoma chromosomal proteins
AU - Lambert, M. W.
AU - McGuire, J.
N1 - Funding Information:
Nuclear proteins have been widely hypothesized to play a significant role in regulation of transcription in eukaryotic cells (1-5]. The manner in which these histones and nonhistone chromosomal proteins (NHPS) interact with each other and/ or DNA to modify and regulate this process is, however, unclear. The present study was undertaken to examine the influence of NHPs and histones on transcription in melanoma cells. Elucidation of the role of these nuclear proteins in regulation of transcription may be important for development of an understanding of the mechanism(s) which dictate gene expression in melanoma cells. We have previously isolated his tones and 4 major NHP fractions from cultivated Cloudman mouse melanoma cells and have shown that the synthesis and/or transport of several NHP subfractions increases in the presence of melanocyte stimulating hormone (MSH) (6]. If these proteins are regulatory they should have a high affinity for DNA and influence DNA template activity. In the present work we have utilized an in vitro system in which histones and/or various NHP fractions are reassociated to homologous DNA and have examined the RNA synthesized from this template. A number of different lines of evidence have demonstrated the fidelity of chromatin reconstitution and support t he contention that chromatin can be reconstituted without significantly disrupting the structural or transcriptional integrity of the genome [7-11]. Though care is required in comparing these experiments to in vivo events, this system permits the examination of the influence of chromatin-associ- Manuscript received July 13, 1981; accepted for publication December 1, 1981. This work was supported by U.S. Public Health Service. Grant 5T01 AM 5264 and 5R01 AM 13929 and by a grant from the Foundation of the College of Medicine and Dentistry of New Jersey. Reprint requests to:. Dr. Muriel Wikswo Lambert, Department of Pathology, UMDNJ-New Jersey Medical School, 100 Bergen Street, Newark, New Jersey 07103. Abbreviations: MSH: melanocyte stimulating hormone NHPS: nonhistone chromosomal proteins SDS: sodium dodecyl su.lfate ated proteins on the regulation of transcription. Our findings indicate that there are nonhistone proteins in melanoma cells which have a high affinity for DNA and which restrict transcription, permitting synthesis of only a few specific sizes of RNA, and that for at least one of the NHPs this effect is enhanced by histones.
PY - 1982
Y1 - 1982
N2 - Histones and 4 nuclear nonhistone protein fractions (NHP(1-4)) were extracted from nuclei of a Cloudman mouse melanoma cell line (NCTC 3960m, CCL 53) and tested for their ability to bind to DNA and influence transcription. The histones and NHP fractions showed different binding affinities for DNA, with the histones and NHP1 exhibiting the highest affinity. The NHP fractions differentially affected both the rate of RNA synthesis and the size of RNA transcribed. NHP1 which inhibited RNA synthesis to the greatest extent, inhibited synthesis of all sizes of RNA except for major peaks of 28S and 8S RNA and discrete minor peaks of 7S, 6S, 5S, and 4S RNA. Histones markedly enhanced the effect of NHP1 on RNA synthesis. These results suggest that there are nonhistone proteins in Cloudman melanoma nuclei which have a high affinity for DNA and which may be involved in the regulation of transcription.
AB - Histones and 4 nuclear nonhistone protein fractions (NHP(1-4)) were extracted from nuclei of a Cloudman mouse melanoma cell line (NCTC 3960m, CCL 53) and tested for their ability to bind to DNA and influence transcription. The histones and NHP fractions showed different binding affinities for DNA, with the histones and NHP1 exhibiting the highest affinity. The NHP fractions differentially affected both the rate of RNA synthesis and the size of RNA transcribed. NHP1 which inhibited RNA synthesis to the greatest extent, inhibited synthesis of all sizes of RNA except for major peaks of 28S and 8S RNA and discrete minor peaks of 7S, 6S, 5S, and 4S RNA. Histones markedly enhanced the effect of NHP1 on RNA synthesis. These results suggest that there are nonhistone proteins in Cloudman melanoma nuclei which have a high affinity for DNA and which may be involved in the regulation of transcription.
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U2 - 10.1111/1523-1747.ep12510312
DO - 10.1111/1523-1747.ep12510312
M3 - Article
C2 - 7086170
AN - SCOPUS:0019976095
SN - 0022-202X
VL - 78
SP - 498
EP - 502
JO - Journal of Investigative Dermatology
JF - Journal of Investigative Dermatology
IS - 6
ER -