Disease relevance of ALG7

• The gene gpt encoding uridine diphosphate N-acetyl-D-glucosamine:dolichol phosphate N-acetylglucosaminylphosphoryltransferase (L-G1PT) was isolated by screening a Schizosaccharomyces pombe genomic DNA library in lambda phage under low-stringency hybridization using the Saccharomyces cerevisiae gene ALG7 as probe [1].

High impact information on ALG7

• Expression of the coding region of the GPT in transformed yeast cells and subsequent transport experiments with the purified protein demonstrated that the GPT protein mediates a 1:1 exchange of glucose 6-phosphate mainly with inorganic phosphate and triose phosphates [2].
• Glucose 6-phosphate imported via the GPT can thus be used either for starch biosynthesis, during which process inorganic phosphate is released, or as a substrate for the oxidative pentose phosphate pathway, yielding triose phosphates [2].
• Analysis of the primary sequences of the cDNAs revealed that the GPT proteins have a high degree of identity with each other but share only approximately 38% identical amino acids with members of both the triose phosphate/phosphate translocator (TPT) and the phosphoenolpyruvate/phosphate translocator (PPT) families [2].
• (ii) The ALG7 and DPM1 proteins are known to recognize the isoprenoid region of dolichol phosphate specifically; this recognition presumably occurs in the membrane since dolichol is very hydrophobic [3].
• Protein glycosylation in yeast: transcript heterogeneity of the ALG7 gene [4].

Biological context of ALG7

• Deregulation of the first N-glycosylation gene, ALG7, perturbs the expression of G1 cyclins and cell cycle arrest in Saccharomyces cerevisiae [5].
• In Saccharomyces cerevisiae, ALG7 has been shown to play a role in cell proliferation [5].
• The ALG7 and TUN1 genes both map on chromosome VII [6].
• In contrast, cell division arrest late in G1, at START, was accompanied by a selective downregulation of only the first dolichol pathway gene, ALG7, and not of the genes functioning later in the pathway [7].
• The Saccharomyces cerevisiae ALG7, ALG1 and ALG2 genes, whose products function early in the dolichol pathway of protein N-glycosylation, are essential for cell viability, and perturbation in their expression causes G1-specific cell cycle arrest [8].

Anatomical context of ALG7

• The gene for the human dolichol cycle GlcNAc-1-P transferase (ALG7/GPT) was cloned by screening a human lung fibroblast cDNA library [9].
• In Chinese hamster ovary cells (CHO), ALG7 gives rise to three mRNAs of 1.5, 1.9 and 2.2 kb [10].
• ALG7 is an early growth-response gene in yeast, and downregulation of ALG7 expression results in diminished N-glycosylation and secretion of Xenopus oocyte proteins [11].

Associations of ALG7 with chemical compounds

• We identified a gene, ALG7, that is probably the structural gene for UDP-N-acetylglucosamine-1-P transferase, the enzyme inhibited by tunicamycin [6].
• Consistent with this, rapid degradation of ALG7, ALG1 and ALG2 mRNAs was completely abolished in the presence of cycloheximide [8].
• Using a temperature-sensitive RNA polymerase II mutant, we demonstrate that increased stability was the primary determinant of higher ALG7 mRNA abundance in response to glucose limitation or treatment with tunicamycin [12].
• The alg7 mutants did not grow on glycerol and DNA arrays revealed the absence of mitochondrial genes' expression [13].
• Sequence of a cDNA that specifies the uridine diphosphate N-acetyl-D-glucosamine:dolichol phosphate N-acetylglucosamine-1-phosphate transferase from Chinese hamster ovary cells [14].

Analytical, diagnostic and therapeutic context of ALG7

• Furthermore, the data suggest multiple genetic targets for ALG7 and provide the basis for future dissection of these developmentally relevant pathways [15].
• Amplification and molecular cloning of the hamster tunicamycin-sensitive N-acetylglucosamine-1-phosphate transferase gene. The hamster and yeast enzymes share a common peptide sequence [16].
• Using a cloned segment of the yeast ALG-7 gene, which encodes the putative GPT from yeast, an amplified gene was identified by Southern blotting of the CHO DNA and a 6.6-kilobase segment of the gene was molecularly cloned [16].

References