Open AccessCross‐linked proteins associated with a specific mRNA in the cytoplasm of HeLa cells
Author(s) -
RUZDIJIC Sabera,
BAG Jnanankur,
SELLS Bruce H.
Publication year - 1984
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1984.tb08277.x
Subject(s) - messenger rna , histone , p bodies , polysome , biology , messenger rnp , cytoplasm , microbiology and biotechnology , rna , histone h2a , biochemistry , translation (biology) , ribosome , gene
Cytoplasmic messenger RNAs of eukaryotic cells are distributed between polysomal and post‐polysomal fractions (free) as protein‐bound complexes. These studies were designed to determine whether a specific mRNA isolated from difrerent subcellular compartments is Complexed with the same family of polypeptides. As a first approach we have examined the proteins associated with mRNA which codes for histone H4. To perform these experiments HeLa cells were exposed to ultraviolet light to cross‐link in vivo polypeptides which are closely associated with nucleic acid. To identify the polypeptides associated with mRNA specific for histones a genomic probe for histone H4 mRNA was immobilized on epoxy‐cellulose. By hybrid selection specific mRNPs containing histone mRNA were isolated. Our results reveal the existence of a number of polypeptides associated with both polysomal and post‐polysomal histone mRNAs. In polysomal histone mRNA two polypeptides of M r = 49000 and 52500 were the major components. In contrast polypeptides of M r = 43000 and 57000 were the major polypeptide components of post‐polysomal (or free) histone mRNA. Furthermore, these results also suggest that the polypeptides associated with either polysomal or free H4 histone mRNA represent a subset of proteins found in poly(A)‐free fractions or poly (A)‐rich mRNA fractions.