Identification of Pea Leaf Nuclear PGK, GAPD & Aldolase Isoforms

University Of Illinois At Chicago, Chicago IL

Investigators

Abstract

Louise Anderson P-glycerate kinase, glyceraldehyde-3-P dehydrogenase, and aldolase, or their antigenic analogs, are present in the nucleus of pea leaf mesophyll cells. The kinase appears to be a subunit of the primer recognition protein involved in lagging strand synthesis. The dehydrogenase may be a part of this same complex and/or may have additional functions related to nucleotide binding. Aldolase might have a function related to DNA-binding. It is not known whether the nuclear proteins are the chloroplast Calvin cycle (reductive pentose phosphate pathway) isozymes or the cytosolic isozymes. The isozymes present in the nucleus will be identified using mono-specific, isozyme-specific antibodies. These experiments will be important to understanding the regulation of nucleic acid metabolism and gene expression in the plant nucleus and in the chloroplast. The antibodies will also be used in co-localization studies. The investigator has found three enzymes in the nucleus that appear to be the same as three enzymes found in the chloroplast or in the cytosol. The surprising aspect of this discovery is that the functions of the nuclear enzymes must differ markedly from those of their chloroplast and cytosolic counterparts, which are known to function in carbon metabolism. The investigator will rigorously compare and identify these enzymes from the different cellular areas.This work will lay the foundation for future studies of the possible roles of these nuclear enzymes in nuclear metabolism and gene regulation.