Ethanol‐Mediated Post‐transcriptional Regulation of ST6Gal 1 (2, 6‐ST) mRNA in Rat Liver: Involvement of a Specific Cytosol Binding Protein that Interacts with the 3′‐Untranslated Region of the mRNA

• Published in: The FASEB journal 2006-03, Vol.20 (4), p.A68-A68
• Main Authors: Garige, Mamatha, Gong, Maokai, Lakshman, Raj
• Format: Article
• Language: English
• ISSN: 0892-6638; 1530-6860
• DOI: 10.1096/fasebj.20.4.A68-b

We have identified a specific binding protein that interacts with the 3′‐UTR of 2,6‐ST mRNA and protects it from degradation in normal rat liver, whereas chronic ethanol feeding decreases the level of this protein. Using [32P] labeled RNA probes generated from a 2.7 kb 3′‐UTR of 2, 6‐ST mRNA, we have now identified a protein that specifically binds to 2, 6‐ST mRNA, but not to 2, 8‐ST mRNA. Proteinase K pretreatment of the protein for 30 min or pre‐heating it at 56°C for 10 min completely abolished the binding. The secondary structure of the RNA was not critical for this binding. UV‐cross linking of the RNA‐protein complex followed by SDS PAGE as well as Northwestern analysis of this protein revealed it to be around 41 kDa protein. The minimum length of the 3′‐UTR of 2, 6‐ST mRNA was 304 bp. Four RNA probes of 80 bp length spanning the entire 304 bp probe showed equal binding intensity. The corresponding cDNA sequences for the four 80 base pair RNA probes share the 13 base pair consensus sequences that may be the specific binding site for this protein(s). RNA‐protein complex formation progressively decreased with increasing dietary ethanol leading to its virtual disappearance with 36% of the total calories as ethanol. Therefore, we conclude that chronic alcohol feeding destabilizes 2,6‐ST mRNA level by decreasing the amount of a specific binding protein/s that interact/s with the specific region in the 3′‐UTR of 2,6‐ST mRNA (Supported by NIH grant AA08149).