Anaerobic expression of maize glucose phosphate isomerase I.

P M Kelley,M Freeling

doi:10.1016/s0021-9258(17)43714-8

Abstract

Anaerobic treatment of maize seedlings results in the selective expression of 10 major and 10 minor polypeptides designated as anaerobic polypeptides (ANPs) (Sachs, M. M., Freeling, M., and Okimoto, R. (1980) Cell 20, 761-767). Enzymatic functions have been ascribed to two of these polypeptides, alcohol dehydrogenases I and II. This report identifies a third anaerobic polypeptide, a maize glucose phosphate isomerase. Glucose phosphate isomerase specific activity increased 60% in 24 h of anaerobiosis and to more than twice its original level in 72 h. Antiserum to spinach cytoplasmic glucose phosphate isomerase 1) was monospecific against maize protein, 2) reduced glucose phosphate isomerase activity in maize extracts by 60%, and 3) recognized a single polypeptide selectively labeled with [35S]methionine during anaerobiosis. This polypeptide co-purified with the major glucose phosphate isomerase of maize. Maize glucose phosphate isomerase co-migrated on two-dimensional polyacrylamide gels with ANP55, the anaerobic polypeptide with a molecular weight of 55,000 on sodium dodecyl sulfate-polyacrylamide gels. Electrophoretically distinguishable alleles of Phi 1 (phosphohexoisomerase-1 gene located at maize chromosome 1L-140) predictably altered the electrophoretic behavior of ANP55, thus proving that Phi 1 encodes ANP55 and that ANP55 is a glucose phosphate isomerase.

Highlights

Anaerobic treatment of maiszeeedlingsresults in the mined by gelfiltration)
Pyruvate decarboxylase is induced by anaerobiosis (Wignarajah and Greenway, 1976; Laszlo, 1981).We report here that a proteinpreviously called ANP55 conditions previously described (Green and Phillips, 1975)
Induction of Glucose Phosphate Zsomerase Activity during Anaerobiosis-The specific activity of glucose phosphate isomerase increased during anaerobiosis by 60% after 24 h and more than 2-fold after 72 h (Table I)

Summary

Anaerobic Expressionof Maize Glucose Phosphate IsomerasIe*

Goodman and co-workers (1980)have selective expression of 10 majorand 10 minor poly- identified electrophoretic variants of maize glucospehosphate peptides designatedas anaerobic polypeptides (ANPs) isomerase I and mapped the enzyme locus (Phil) 12 map Enzymatic functions have been as- and Gottlieb (1982) purified both cytosolic and plastid forms cribed to two of these polypeptides, alcohol dehydro- of glucose phosphate isomerase from spinach. Amide gels with ANP55, theanaerobicpolypeptide W629 and Tx325, were used to compare electrophoretic variants of with a molecular weight of 55,000 on sodium dodecyl maize glucosephosphate isomerase They were a gift from Dr Major sulfate-polyacrylamide gels. Peptides are synthesized exclusively (Sachs et al, 1980).Two Tissue culture cells were maintained at 27 "C in media and under of the major polypeptides were identified as the alcohol dehydrogenases, products of the Adhf and Adh genes (Sachs and Freeling, 1978).

Anaerobic Expressionof Maize GlucosePhosphate Isomerase I

RESULTS

Glucose phosphate isomerase

DISCUSSION