The glyoxylate cycle switches fatty acid utilization from energy production to biosynthesis. The predicted polypeptide sequence is 1005 amino acids long, with a molecular weight of 112,799. The ICL and MS domains are contiguous in genomic DNA and are separated by a 68 bp intron. The physical localization of the gene correlates with a small region of the left arm of Linkage Group V. Multiple embryonic lethal mutations have been mapped to this region. Characterization of GCP expression indicates that it is regulated at multiple levels, spatial, temporal and environmental.
Spatial regulation localizes expression to gut and muscle cell lineages.
GCP antigen is first detectable in 4-6 cells of the clonal E lineage of 100 cell embryos. This lineage is committed to the intestinal cell fate. Temporal regulation induces expression of GCP mRNA, protein and enzymatic activities during embryonic and larval stages. ICL and MS enzymatic activities have been shown by others to be highest in embryos and Ll larvae. We demonstrate that GCP mRNA and protein levels rise during embryogenesis and peak during larval stages.