The role of primer recognition proteins in DNA replication: association with nuclear matrix in HeLa cells

摘要: Primer recognition proteins (PRP) enable DNA polymerase alpha to utilize efficiently substrates with low primer template ratios. We have previously identified the protein-tyrosine kinase substrate annexin II, and glycolytic enzyme 3-phosphoglycerate as components of PRP. As a step towards elucidation role PRP in process replication, we investigated subcellular distribution specific association these nuclear matrix HeLa cells. Nuclear extracts prepared from cells S phase contain enzymatic activity (PGK) phospholipase A2 inhibitory II. Monomer II is approximately equally distributed between cytoplasmic fractions, while majority PGK cytoplasm. Immunoblot analyses reveal presence two nuclei, specifically associated matrix. This further confirmed by observation isolated matrices immunoelectron microscopy. The colocalizes matrix-bound A related protein, I, not detectable slower-migrating (perhaps modified) form found be Attempts dissociate octyl-beta-glucoside, high salt or metal ion chelators were unsuccessful, suggesting that interaction very strong.