A 28 KDa protein was isolated from bovine brain lysate by affinity chromatography using peptides mimicking the C-terminus of the Type-I Insulin-like Growth Factor Receptor (IGF-IR). This protein specifically recognizes IGF-IR peptides including phosphorylation of the Tyr-1251 residue, whose integrity is required for the transforming activity of the receptor. On the basis of partial protein sequencing, a synthetic peptide was used to generate specific antibodies. These were used to screen a bovine brain expression library, leading to the isolation of a 1.0 Kb cDNA including a 600 bp ORF coding for the whole 28 KDa protein. Comparative sequence analysis demonstrated that this protein corresponds to the bovine methenyltetrahydrofolate synthetase (MTHFS), the enzyme that catalyses the ATP-dependent transformation of 5-formyltetrahydrofolate (5-FTHF) to 5,10-methenyltetrahydrofolate. The MTHFS gene was first mapped in the human genome by PCR amplification of DNA isolated from a human/rodent somatic cell hybrid panel, and was assigned to the human chromosome 15q24. The chromosomal localization was confirmed by fluorescence in situ hybridization (FISH) analysis. Since the level of 5-FTHF regulates the folate metabolism homeostasis and influence homocysteine remethylation, the activity of the MTHFS might be important for the complete closure of the neural tube during development.
Cloning and chromosome localization of the gene for the methenyltratrahydrofolate-synthetase
RUBINI, Michele;BONONI, Ilaria;CALZOLARI, Elisa
1999
Abstract
A 28 KDa protein was isolated from bovine brain lysate by affinity chromatography using peptides mimicking the C-terminus of the Type-I Insulin-like Growth Factor Receptor (IGF-IR). This protein specifically recognizes IGF-IR peptides including phosphorylation of the Tyr-1251 residue, whose integrity is required for the transforming activity of the receptor. On the basis of partial protein sequencing, a synthetic peptide was used to generate specific antibodies. These were used to screen a bovine brain expression library, leading to the isolation of a 1.0 Kb cDNA including a 600 bp ORF coding for the whole 28 KDa protein. Comparative sequence analysis demonstrated that this protein corresponds to the bovine methenyltetrahydrofolate synthetase (MTHFS), the enzyme that catalyses the ATP-dependent transformation of 5-formyltetrahydrofolate (5-FTHF) to 5,10-methenyltetrahydrofolate. The MTHFS gene was first mapped in the human genome by PCR amplification of DNA isolated from a human/rodent somatic cell hybrid panel, and was assigned to the human chromosome 15q24. The chromosomal localization was confirmed by fluorescence in situ hybridization (FISH) analysis. Since the level of 5-FTHF regulates the folate metabolism homeostasis and influence homocysteine remethylation, the activity of the MTHFS might be important for the complete closure of the neural tube during development.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
