Literature summary for 6.3.2.17 extracted from

Yang, C.; Xie, L.Y.; Windle, J.J.; Taylor, S.M.; Moran, R.G.
Humanizing mouse folate metabolism conversion of the dual-promoter mouse folylpolyglutamate synthetase gene to the human single-promoter structure (2014), FASEB J., 28, 1998-2008 .

Cloned(Commentary)

Cloned (Comment)	Organism
gene fpgs, the mouse uses two promoters: P2, akin to the human promoter, at low levels in most tissues, and P1, an upstream promoter used extensively in liver and kidney. In mice, 2 additional exons (A1a and A1b), 10 kb upstream of the 15 exons homologous to those of the human gene, are used in place of exon 1 when an associated promoter (P1) is activated. The mouse fpgs gene transcribes strongly and predominantly from the P1 promoter in liver and kidney, the 2 major folate storage organs, but its transcription initiates exclusively from the proximal promoter (P2) in all other murine tissues, tumors, and cell lines, indicating liver- and kidney-specific transcription factors for P1 promoter usage. In mouse P2, the behavior and distribution of transcription factor binding sites are very similar to those of the human promoter. Two contiguous HindIII genomic DNA fragments containing the mouse fpgs promoters are cloned previously from a mouse 129/sv bacterial artificial chromosome (BAC) library including the promoter P1 or P2 sequences, respectively, P1 is cloned into the P1-A1aA1b targeting vector for generation of embryonic stem (ES) cells with P1 conditional- or complete-KO fpgs allele. Determination of the stability and translation efficiency of the proteins made from P1 and P2 promoters	Mus musculus

Cloned (Comment)

Organism

gene fpgs, the mouse uses two promoters: P2, akin to the human promoter, at low levels in most tissues, and P1, an upstream promoter used extensively in liver and kidney. In mice, 2 additional exons (A1a and A1b), 10 kb upstream of the 15 exons homologous to those of the human gene, are used in place of exon 1 when an associated promoter (P1) is activated. The mouse fpgs gene transcribes strongly and predominantly from the P1 promoter in liver and kidney, the 2 major folate storage organs, but its transcription initiates exclusively from the proximal promoter (P2) in all other murine tissues, tumors, and cell lines, indicating liver- and kidney-specific transcription factors for P1 promoter usage. In mouse P2, the behavior and distribution of transcription factor binding sites are very similar to those of the human promoter. Two contiguous HindIII genomic DNA fragments containing the mouse fpgs promoters are cloned previously from a mouse 129/sv bacterial artificial chromosome (BAC) library including the promoter P1 or P2 sequences, respectively, P1 is cloned into the P1-A1aA1b targeting vector for generation of embryonic stem (ES) cells with P1 conditional- or complete-KO fpgs allele. Determination of the stability and translation efficiency of the proteins made from P1 and P2 promoters

Mus musculus

Protein Variants

Protein Variants	Comment	Organism
additional information	construction of homologous recombination vectors for conditional and complete deletion of the fpgs P1 promoter and the associated exons, conversion of the dual-promoter mouse folylpolyglutamate synthetase gene to the human single-promoter structure. Deletion of the mouse P1 promoter through homologous recombination to study the dual-promoter mouse system and to create a mouse with a humanized fpgs gene structure reveals that despite the loss of the predominant fpgs mRNA species in liver and kidney, P1-knockout mice develop and reproduce normally. The survival of the mutant mice is explained by increased P2 transcription due to relief of transcriptional interference, by a 3fold more efficient translation of P2-derived than P1-derived transcripts, and by 2fold higher stability of P2-derived FPGS. In combination, all 3 effects reinstate FPGS function, even in liver. Eliminating mouse P1 gives a mouse model that mimicks the human housekeeping pattern of fpgs gene expression. Generation of embryonic stem (ES) cells with P1 conditional- or complete-KO fpgs allele, and generation of homozygous P1-knockout mice, Recombinant expression of enzyme constructs in the enzyme-deficient AUXB1 cell from Cricetulus griseus	Mus musculus

Metals/Ions

Metals/Ions	Comment	Organism	Structure
Mg2+	required	Mus musculus

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
ATP + tetrahydropteroyl-[gamma-Glu]n + L-glutamate	Mus musculus	-	ADP + phosphate + tetrahydropteroyl-[gamma-Glu]n+1	-	?

Organism

Organism	UniProt	Comment	Textmining
Mus musculus	P48760	-	-

Source Tissue

Source Tissue	Comment	Organism	Textmining
kidney	75% of fpgs transcripts	Mus musculus	-
liver	95% of fpgs transcripts	Mus musculus	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
ATP + tetrahydropteroyl-[gamma-Glu]n + L-glutamate	-	Mus musculus	ADP + phosphate + tetrahydropteroyl-[gamma-Glu]n+1	-	?

Synonyms

Synonyms	Comment	Organism
Folylpolyglutamate synthetase	-	Mus musculus
FPGS	-	Mus musculus

Cofactor

Cofactor	Comment	Organism	Structure
ATP	-	Mus musculus

General Information

General Information	Comment	Organism
malfunction	deletion of the mouse P1 promoter through homologous recombination creates a mouse with a humanized fpgs gene structure, despite the loss of the predominant fpgs mRNA species in liver and kidney (representing 95% and 75% of fpgs transcripts in these tissues, respectively), P1-knockout mice develop and reproduce normally. The survival of the mutant mice is explained by increased P2 transcription due to relief of transcriptional interference, by a 3fold more efficient translation of P2-derived than P1-derived transcripts, and by 2fold higher stability of P2-derived FPGS. In combination, all 3 effects reinstate FPGS function, even in liver. Eliminating mouse P1 gives a mouse model that mimicks the human housekeeping pattern of fpgs gene expression. P1-knockout mice have a normal phenotype and only minor changes in folate metabolism, phenotype, P1-knockout mice assume a humanized fpgs expression pattern, detailed overview	Mus musculus
physiological function	the folylpoly-gamma-glutamate synthetase (fpgs) gene product determines folate/antifolate intracellular retention and antifolate antitumor activity, and displays a pronounced species difference. The folate cofactors mediate 1-carbon transfer reactions that are essential for all living organisms. In mammals, as circulating folates penetrate the plasma membrane, they are promptly converted into polyglutamate metabolites by folylpoly-gamma-glutamate synthetase (FPGS), a metabolic conversion that promotes intracellular retention of these essential cofactors and their affinity for some folate cofactor-dependent enzymes	Mus musculus