The mRNAs for cyclin A, c-myc and ribosomal proteins L4 and S6 are associated with cytoskeletal-bound polysomes in HepG2 cells

Biochem J. 1995 Aug 15;310 ( Pt 1)(Pt 1):193-6. doi: 10.1042/bj3100193.

Abstract

Cytosolic, cytoskeleton and membrane fractions were extracted from HepG2 cells by a sequential detergent/salt extraction procedure. The cytosolic fraction contained 93% of the lactic dehydrogenase activity while the cytoskeleton fraction was enriched in actin and vimentin. The distribution of mRNAs for c-myc, glucose transporter 1, ribosomal proteins L4 and S6 and cyclin A were investigated by Northern hybridization of total RNA extracted from polysomes isolated from cytosolic, cytoskeleton and membrane fractions. The membrane-bound polysomes were enriched in the glucose transporter 1 mRNA and the cytoskeleton-bound polysomes were enriched in the mRNAs for the two ribosomal proteins, c-myc and cyclin A. The results suggest that the mRNAs for nuclear proteins are one class of mRNAs which are translated on polysomes associated with the cytoskeleton; this may be related to the requirement to transport the newly synthesized protein to the nucleus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Membrane / metabolism
  • Cyclins / genetics*
  • Cyclins / metabolism
  • Cytoskeleton / metabolism
  • Humans
  • Polyribosomes / metabolism
  • Proto-Oncogene Proteins c-myc / genetics*
  • Proto-Oncogene Proteins c-myc / metabolism
  • RNA, Messenger / metabolism*
  • Ribosomal Protein S6
  • Ribosomal Proteins / genetics*
  • Ribosomal Proteins / metabolism
  • Tumor Cells, Cultured

Substances

  • Cyclins
  • Proto-Oncogene Proteins c-myc
  • RNA, Messenger
  • Ribosomal Protein S6
  • Ribosomal Proteins
  • ribosomal protein L4