Association of betaine-homocysteine S-methyltransferase with microtubules.
In mammals, betaine of the mitochondrial matrix is used in the cytosol by betaine-homocysteine S-methyltransferase for methionine synthesis. The resulting dimethylglycine is shuttled back into the mitochondrial matrix for further degradation. Nanospray tandem mass spectrometry and N-terminal amino acid sequencing of microtubule-associated proteins from rat liver tubulin revealed that betaine-homocysteine S-methyltransferase is microtubule associated. This was confirmed by confocal laser scanning microscopy of HepG2 cells labeled with betaine-homocysteine S-methyltransferase- and alpha-tubulin-specific monoclonal antibodies. The association of betaine-homocysteine S-methyltransferase with the cytoskeleton may functionally integrate the mitochondrial and cytoplasmic compartments of choline degradation.
Sandu
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C
Institut für Biochemie und Molekularbiologie, Universität Freiburg, Germany.
Nick
P
P
Hess
D
D
Schiltz
E
E
Garrow
T A
TA
Brandsch
R
R
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D005455:Fluorescent Antibody Technique; D050904:Homocysteine S-Methyltransferase; D008099:Liver / Q000201:enzymology; D008780:Methyltransferases / Q000737:chemistry / Q000378:metabolism*; D008870:Microtubules / Q000201:enzymology*; D051381:Rats
D008780:Methyltransferases; D050904:Homocysteine S-Methyltransferase