title: Characterization of mutant serine palmitoyltransferase 1 in LY-B cells.
abstract: CHO-LY-B cells have been useful in studies of sphingolipid metabolism and function because they lack serine palmitoyltransferase (SPT) activity. Cloning and sequencing of the SPT1 transcript of LY-B cells identified the mutation as a guanine to adenine change at nucleotide 738, causing a G246R transformation. Western blots revealed low expression of the mutant SPT1 peptide, but activity was not detectable by mass spectrometric analysis of [(13)C]-palmitate incorporation into sphinganine, sphingosine, 1-deoxysphinganine, or 1-desoxymethylsphinganine. Treatment of LY-B cells with chemical chaperones (DMSO or glycerol) increased the amounts of mutant SPT1 as well as SPT2, but SPT activity was not restored. This study has established that G246R mutation in hamster SPT1 results in the loss of SPT activity.
authors.affiliation: School of Biology, The Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA.
authors.forename: Amin A
authors.initials: AA
authors.lastname: Momin
authors.forename: Hyejung
authors.initials: H
authors.lastname: Park
authors.forename: Jeremy C
authors.initials: JC
authors.lastname: Allegood
authors.forename: Martina
authors.initials: M
authors.lastname: Leipelt
authors.forename: Samuel L
authors.initials: SL
authors.lastname: Kelly
authors.forename: Alfred H
authors.initials: AH
authors.lastname: Merrill
authors.forename: Kentaro
authors.initials: K
authors.lastname: Hanada
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D002460:Cell Line; D003001:Cloning, Molecular; D006224:Cricetinae; D003412:Cricetulus; D008958:Models, Molecular; D050505:Mutant Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D055550:Protein Stability; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D051102:Serine C-Palmitoyltransferase / Q000032:analysis / Q000737:chemistry* / Q000235:genetics*
chemical_list: D050505:Mutant Proteins; D051102:Serine C-Palmitoyltransferase