Nuclear localization of a lactic dehydrogenase with single-stranded DNA-binding properties.

In the preceding article [1] we identified the 34 kD single-stranded DNA-binding (ssb) protein, whose synthesis is inhibited in PC12 cells concomitantly with nerve growth factor (NGF)-induced mitotic arrest, with the enzyme lactic dehydrogenase (LDH-ssb protein). Localization studies performed with antibodies raised against the LDH-ssb protein demonstrate the presence of a pool of this protein in the nucleus of several cell types. The nuclear association of this protein is sensitive to DNase treatment of the cells and quantitative electron microscopy confirms that the LDH-ssb protein is located close to chromatin structures. These results point to a possible involvement of the LDH-ssb protein in some nuclear function(s).