Free, cytoskeletal-bound and membrane-bound polysomes isolated from MPC-11 and Krebs II ascites cells differ in their complement of poly(A) binding proteins

Mol Cell Biochem. 1994 Feb 23;131(2):131-9. doi: 10.1007/BF00925949.

Abstract

A three-step detergent/salt extraction procedure (Vedeler et al., Mol Cell Biochem 100: 183-193, 1991) was used to isolate free polysomes (FP), cytoskeletal-bound polysomes (CBP) and membrane-bound polysomes (MBP) from MPC-11 and Krebs II ascites cells. Polysomes were pelleted, washed with high salt buffer and re-pelleted. Proteins in the dialysed high-salt extracts were subjected to poly(A) Sepharose chromatography and poly(A) binding and non-binding proteins were separated by SDS-PAGE. In MPC-11 cells the FP fraction contains thirteen poly(A) binding proteins and four non-poly(A) binding proteins while the corresponding fraction in Krebs II ascites cells has four poly(A) binding proteins and six proteins which do not bind poly(A). The CBP fraction isolated from MPC-11 cells has a complement of ten poly(A) binding proteins, four which are non-poly(A) binding, and a protein of 105 kDa which has both poly(A) binding and non-poly(A) binding properties. In the CBP fraction prepared from Krebs II ascites cells a protein band at 32 kDa exhibits both poly(A) binding and non-poly(A) binding properties. In this fraction there are six poly(A) binding proteins and an additional eight which do not bind poly(A). Of the total number of proteins eight of these have a molecular weight below 40 kDa. The MBP fraction in MPC-11 cells contains three poly(A) binding proteins and eleven with non-poly(A) binding properties. In contrast this fraction in Krebs II ascites cells has a complement of thirteen poly(A) binding and ten non-poly(A) binding proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3 Cells
  • Animals
  • Ascites
  • Cell Division
  • Cell Membrane / chemistry*
  • Cell Separation
  • Cell-Free System
  • Chromatography, Affinity
  • Cytoskeleton / chemistry*
  • Mice
  • Poly(A)-Binding Proteins
  • Polyribosomes / chemistry*
  • RNA-Binding Proteins / analysis*
  • Tumor Cells, Cultured

Substances

  • Poly(A)-Binding Proteins
  • RNA-Binding Proteins