Aldolase-DNA interactions in a SEWA cell system

Abstract

In this report we demonstrate the novel finding that aldolase A interacts with DNA sequences in mouse SEWA sarcoma cells. This interaction was initially observed through the identification of a 40 kDa protein which was eluted from a DNA affinity chromatography column consisting of the long terminal repeat (LTR) of the endogenous intracisternal A-type particle (IAP). Microsequencing analysis identified this 40 kDa protein as the glycolytic enzyme, aldolase A. The use of specific anti-aldolase antibodies enabled the identification and subsequent purification of aldolase from the nuclear protein fraction of two SEWA sublines, one that is adherent and one that grows in suspension. In order to confirm our initial finding that aldolase is capable of interacting with DNA, proteins from each subline were immunopurified with anti-aldolase antibodies, eluted and then tested for their ability to interact with IAP-LTR DNA sequences. Interestingly, only aldolase derived from the anchorage dependent SEWA cells was capable of interacting with the IAP-LTR, however, several cell lines derived from human tumors also exhibited this activity. Subsequent studies revealed the ability of aldolase to interact with some but not every DNA sequence tested, implying that there may be a minimal DNA conformation and/or sequence requirement for this activity. The presence of aldolase A in the nuclei and its ability to interact with certain DNA sequences suggest a novel role for this metabolic enzyme.