Syntheses and modulations in the chromatin contents of histones H1/sup o/ and H1 during G/sub 1/ and S phases in Chinese hamsters cells

Journal Article · Tue Aug 17 04:00:00 EDT 1982 · Biochemistry; (United States)

OSTI ID:6342411

D'Anna, J A; Gurley, L R; Tobey, R A

Flow cytometry, conventional autoradiography, and autoradiography employing high concentrations of high specific activity (/sup 3/H)thymidine indicate that (1) treatment of Chinese hamster ovary (line CHO) cells with butyrate truly blocks cells in G/sub 1/ and (2) cells blocked in G/sub 1/ by isoleucine deprivation remain blocked in G/sub 1/ when they are released into complete medium containing butyrate. Measurements of H1/sup o/ content relative to core histones and H1/sup o/:H1 ratios indicate that H1/sup o/ is enhanced somewhat in G/sub 1/ cells arrested by isoleucine deprivation; however, (1) treatment with butyrate greatly increases the H1/sup o/ content in G/sub 1/-blocked cells, and (2) the enhancement is very sensitive to butyrate concentration. Measurements of relative histone contents in the isolated chromatin of synchronized cultures also suggest that the acid-soluble content of histone H1 (relative to core histones) becomes greatly depleted in the isolated chromatin when synchronized cells are blocked in early S phase by sequential use of isoleucine deprivation and hydroxyurea blockade. We also have measured (/sup 3/H)lysine incorporation, various protein ratios, and relative rates of deposition of newly synthesized H1/sup o/, H1, and H4 onto chromatin during G/sub 1/ and S in the absence of butyrate. The results suggest a dynamic picture of chromatin organization in which (1) newly synthesized histone H1/sup o/ binds to chromatin during traverse of G/sub 1/ and S phases and (2) histone H1 dissociates from (or becomes loosely bound to) chromatin during prolonged early S-phase block with hydroxyurea.

• OSTI ID: 6342411
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 21:17; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMIDES
AMINO ACIDS
ANIMAL CELLS
ANIMALS
AUTORADIOGRAPHY
AZINES
BIOCHEMICAL REACTION KINETICS
BIOSYNTHESIS
BODY
CARBOXYLIC ACIDS
CELL DIVISION
CHROMATIN
FEMALE GENITALS
GONADS
HAMSTERS
HETEROCYCLIC COMPOUNDS
HISTONES
HYDROXY COMPOUNDS
HYDROXYUREA
ISOTOPE APPLICATIONS
KINETICS
LYSINE
MAMMALS
MEIOSIS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
OVARIES
PROTEINS
PYRIMIDINES
REACTION KINETICS
RIBOSIDES
RODENTS
SYNTHESIS
THYMIDINE
TRACER TECHNIQUES
VERTEBRATES