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Title: Late-assembly of human ribosomal protein S20 in the cytoplasm is essential for the functioning of the small subunit ribosome

Using immuno-fluorescent probing and Western blotting analysis, we reveal the exclusive cytoplasm nature of the small subunit ribosomal protein S20. To illustrate the importance of the cellular compartmentation of S20 to the function of small subunit 40S, we created a nuclear resident S20{sub NLS} mutant gene and examined polysome profile of cells that had been transfected with the S20{sub NLS} gene. As a result, we observed the formation of recombinant 40S carried S20{sub NLS} but this recombinant 40S was never found in the polysome, suggesting such a recombinant 40S was translation incompetent. Moreover, by the tactic of the energy depletion and restoration, we were able to restrain the nuclear-resided S20{sub NLS} in the cytoplasm. Yet, along a progressive energy restoration, we observed the presence of recombinant 40S subunits carrying the S20{sub NLS} in the polysome. This proves that S20 needs to be cytoplasmic in order to make a functional 40S subunit. Furthermore, it also implies that the assembly order of ribosomal protein in eukaryote is orderly regulated. - Highlights: • The step of S20 assembled on 40S is happened in the cytoplasm. • A small subunit assembled with a nuclear S20{sub NLS} is translational incompetence. • Using energy depletion andmore » recovery to manipulate the cellular compartment of S20{sub NLS}. • Cytoplasm-retained S20{sub NLS} is crucial for creating a functional small subunit.« less
 [1] ;  [2] ; ;  [1] ;  [1] ;  [3]
  1. Institute of Genome Sciences, School of Life Sciences, National Yang-Ming University, Taipei, Taiwan, ROC (China)
  2. Department of Dentistry, School of Dentistry, National Yang-Ming University, Taipei, Taiwan, ROC (China)
  3. (China)
Publication Date:
OSTI Identifier:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Experimental Cell Research; Journal Volume: 319; Journal Issue: 19; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States