Proteins in Nucleocytoplasmic Interactions
Year: 1967
Type: article
Abstract: By the transplantation of amino acid-(3)H-labeled nuclei between cells and the subsequent isolation of nuclei for quantitative assay, we have confirmed that all the nuclear proteins of Amoeba proteus are divisible into two classes that are sharply defined by their physiological behavior. About 40% of the proteins in the nucleus rapidly migrates back and forth between the nucleus and the cytoplasm. These rapidly migrating proteins (RMP) are 25-50 times more concentrated in the nucleus than in the cytoplasm, and migration into the nucleus therefore occurs against a high concentration differential. The remaining 60% of nuclear proteins has been classified as slow turnover proteins (STP) since (as reported in a following paper) virtually all of them ultimately undergo turnover. Turnover in this context means loss of label from the nucleus, by either protein breakdown or protein migration to the cytoplasm. Isolation of nuclei in the detergent Triton X-100 results in a 20% loss of nuclear proteins but conclusions about RMP and STP were not found to be significantly affected by this loss.
Source: The Journal of Cell Biology
DOI: 10.1083/jcb.33.3.637
Authors: Lester Goldstein, David M. Prescott
Institutions: University of Colorado Boulder, University of Pennsylvania
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2030799269