hnRNPs H, H' and F behave differently with respect to posttranslational cleavage and subcellular localization.
hnRNPs H, H' and F belong to a subfamily of the hnRNPs sharing a high degree of sequence identity. Eukaryotic expression and specific C-terminal antibodies were used to demonstrate great variation in the intracellular fate of the proteins. hnRNPs H and H' become posttranslational cleaved into C-terminal 35 kDa proteins (H(C), H'(C)) and possibly into N-terminal 22 kDa proteins. No detectable cleavage was observed for hnRNP F. hnRNP H/H' is almost exclusively localized to the nucleus of many cell types while hnRNP F varies from a predominant nuclear localization in some cells to a predominant cytoplasmic localization in other cells. The different fates may reflect differences in functional roles that so far only have included nuclear functions. The presence of significant quantities of hnRNP F in the cytoplasm of many cells indicates that it also may have a functional role here.
Honoré
B
B
Department of Medical Biochemistry, Ole Worms Allé, University of Aarhus, Denmark. bh@biokemi.au.dk
Vorum
H
H
Baandrup
U
U
D000595:Amino Acid Sequence; D000818:Animals; D000918:Antibody Specificity; D001483:Base Sequence; D015153:Blotting, Western; D019556:COS Cells; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D005260:Female; D015870:Gene Expression; D034541:Heterogeneous-Nuclear Ribonucleoprotein Group F-H; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics / Q000276:immunology; D011499:Protein Processing, Post-Translational; D011817:Rabbits; D012261:Ribonucleoproteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism; D014018:Tissue Distribution; D014162:Transfection
D017931:DNA Primers; D034541:Heterogeneous-Nuclear Ribonucleoprotein Group F-H; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D010446:Peptide Fragments; D012261:Ribonucleoproteins