Expression of mRNAs encoding mammalian chromosomal proteins HMG-I and HMG-Y during cellular proliferation

Journal Article · Thu Mar 01 00:00:00 EST 1990 · Experimental Cell Research; (United States)

DOI:https://doi.org/10.1016/0014-4827(90)90118-T· OSTI ID:5311913

Johnson, K R; Disney, J E; Wyatt, C R; Reeves, R ^[1]

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1. Washington State Univ., Pullman (United States)

The high mobility group chromosomal proteins HMG-I and HMG-Y are closely related isoforms that are expressed at high levels in rapidly dividing, undifferentiated mammalian cells. The authors analyzed HMG-I/Y mRNA levels at various cell cycle stages in murine NIH/3T3 fibroblasts partially synchronized by seeding from quiescent, contact-inhibited cultures. Flow microfluorometric analysis of DNA content demonstrated a comparable degree of synchronization in such seeded NIH 3T3 cell populations as is obtained by serum deprivation or other means and has the added advantage of avoiding the use of possibly detrimental inhibitors or metabolic starvation to induce such synchrony. They show that HMG-I/Y mRNA levels gradually increase in NIH/3T3 cells during the first 16 hours after seeding (G{sub 0}/G{sub 1} to late S phase), but thereafter remain constant, in contrast to the cell cycle-regulated expression of the histone H3 gene. The HMG-I/Y mRNAs appear to be very stable; there was no decrease in their levels 6 hours after actinomycin D transcription termination. The proportion of HMG-I to HMG-Y mRNAs was greater in the human than in the murine cells examined, appeared to be greater in proliferating than in quiescent cells, and did not always correspond with the HMG-I to HMG-Y protein ratio.

• OSTI ID: 5311913
• Journal Information: Experimental Cell Research; (United States), Vol. 187:1; ISSN 0014-4827
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
FIBROBLASTS
CELL PROLIFERATION
MESSENGER-RNA
TRANSCRIPTION
NUCLEOPROTEINS
GENE REGULATION
ACTINOMYCIN
CELL CYCLE
CELL DIFFERENTIATION
CHROMATIN
ANIMAL CELLS
ANTI-INFECTIVE AGENTS
ANTIBIOTICS
ANTIMITOTIC DRUGS
ANTINEOPLASTIC DRUGS
CONNECTIVE TISSUE CELLS
DRUGS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PROTEINS
RNA
SOMATIC CELLS
550300* - Cytology