Nuclear matrix-associated NMN adenylyltransferase activity in human placenta.

This paper presents data about the presence of the NMN adenylyltransferase at the nuclear matrix level of human placenta nuclei. It was found that 40-45% of the activity (depending on the extraction procedure) referred to the total nuclear NMN adenylyltransferase was tightly associated with this subnuclear compartment. The matrices purified by two different procedures exhibited DNA, RNA and protein contents comparable with those described in literature. Extensive digestion of human placenta nuclei with DNase I was not able to solubilize the NMN adenylyltransferase activity. Therefore, the data we present are consistent with the conclusion that a part of the total nuclear NMN adenylyltransferase is associated with the nuclear matrix.