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Decreased ratio of alpha- to beta-globin mRNA in reticulocyte membrane RNA

V A Mezl, N Cutcliffe

    The International Journal of Biochemistry
    |January 1, 1987
    PubMed

    Insights

    Rabbit reticulocyte membrane-bound ribosomes yield RNA inversely proportional to hematocrit. Membrane RNAs produce a distinct alpha- to beta-globin ratio, differentiating them from cytoplasmic RNAs.

    Area of Science:

    • Molecular Biology
    • Cell Biology
    • Biochemistry

    Background:

    • Ribosomes are crucial for protein synthesis, existing as free or membrane-bound populations.
    • Membrane-bound ribosomes are involved in synthesizing proteins destined for secretion or insertion into membranes.
    • Distinguishing between free and membrane-bound ribosomes is essential for understanding cellular protein production.

    Purpose of the Study:

    • To investigate the characteristics of RNA isolated from rabbit reticulocyte membrane-bound ribosomes.
    • To determine if RNA from membrane-bound ribosomes can be distinguished from cytoplasmic RNA based on translation products.
    • To explore the relationship between animal hematocrit and the yield of membrane-bound ribosome RNA.

    Main Methods:

    • Phenol extraction of RNA from washed rabbit reticulocyte membranes.
    • In vitro translation assays using reticulocyte and wheat germ systems.
    • Analysis of translation products via Triton X-100 acid urea gel electrophoresis.

    Main Results:

    • RNA yield from membrane-bound ribosomes was inversely related to animal hematocrit.
    • A Mr = 30,000 protein, a marker for membrane polysomes, was produced by endogenous mRNA in the translation system.
    • Membrane-bound RNAs exhibited a specific alpha- to beta-globin ratio (0.77), distinct from cytoplasmic polysomal and supernatant RNAs.

    Conclusions:

    • Free and membrane-bound ribosomes can be differentiated by the primary proteins they synthesize.
    • The distinct globin ratio of membrane RNAs suggests specific mRNA populations are associated with membrane-bound ribosomes.
    • Hematocrit levels may influence the abundance of membrane-bound ribosomes in reticulocytes.

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