Ultra-low temperature techniques (microdissection and autoradiography) were used to study the nucleocytoplasmic distribution and transport of alpha-aminoisobutyric acid (AIB) in an amino acid-accumulating cell. In amphibiam oocytes incubated in AIB, the nuclear concentration of this non-metabolizable amino acid exceeds the cytoplasmic concentration by 45%, remaining constant both over time and variation in substrate concentration. The kinetics of uptake suggest that this nucleo-cytoplasmic asymmetry arises from solubility differences between the 2 compartments, and that the nuclear envelope plays a negligible role in amino acid transport. A solute exclusion model is offered to explain the nucleocytoplasmic asymmetry.
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JOURNAL ARTICLE| 01 October 1975
Nucleocytoplasmic transport and distribution of an amino acid, in situ
Online Issn: 1477-9137
Print Issn: 0021-9533
© 1975 by Company of Biologists
J Cell Sci (1975) 19 (1): 127–139.
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M. Frank, S.B. Horowitz; Nucleocytoplasmic transport and distribution of an amino acid, in situ. J Cell Sci 1 October 1975; 19 (1): 127–139. doi: https://doi.org/10.1242/jcs.19.1.127
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