Phosphoglucomutase (EC:5.4.2.2) catalyzes the interconversion of glucose-6-phosphate and glucose-1-phosphate and is important for carbohydrate metabolism in a variety of organisms, ranging from bacteria to humans (4, 5, 1, 6). The direction of the interconversion is determined by the availability of substrate carbon sources (5). Saccharomyces cerevisiae contains a major phosphoglucomutase isoform, Pgm2p, and a minor phosphoglucomutase isoform, Pgm1p. Pgm2p and Pgm1p functions are involved in glycolysis, the pentose phosphate shunt, and the metabolism of glycogen, trehalose, and galactose. Phosphoglucomutase is also required for the synthesis of N-linked glycoproteins, extracellular glycans, and UDP-glucose (4, 5, 6, 7). Phosphoglucomutase also indirectly effects calcium uptake and homeostasis because glucose-1-phosphate and glucose-6-phosphate effect cation uptake (8, 9, 5).

PGM1 is constitutively expressed (5), and pgm1 null mutants are viable (10). pgm1 pgm2 double null mutants are also viable, but cannot use galactose as a sole carbon source, and accumulate lower levels of glycogen and trehalose than wild type (1).

Last updated: 2005-09-08