Temperature-induced changes in the hydroxy and non-hydroxy fatty acid-containing sphingolipids abundant in the surface membrane of Tetrahymena pyriformis NT-1

• Published in: Journal of lipid research 1984-01, Vol.25 (1), p.68-74
• Main Authors: Kaya, K, Ramesha, C S, Thompson, Jr, G A
• Format: Article
• Language: English
• Subjects: Animals; Cell Membrane - metabolism; Fatty Acids - analysis; Hydroxy Acids - analysis; hydroxylation; Kinetics; Membrane Lipids - metabolism; Palmitic Acid; Palmitic Acids - metabolism; sphingolipids; Sphingolipids - isolation & purification; Sphingolipids - metabolism; Structure-Activity Relationship; Temperature; Tetrahymena pyriformis; Tetrahymena pyriformis - metabolism
• ISSN: 0022-2275
• DOI: 10.1016/S0022-2275(20)37845-7

Sphingolipids make up 30 to 40 mole % of the phospholipids found in the surface membrane of Tetrahymena pyriformis NT-1. We have identified the two major classes as non-hydroxy fatty acid-containing ceramide-2-aminoethylphosphonate (NCAEP) and alpha-hydroxy fatty acid-containing ceramide-2-aminoethylphosphonate (HCAEP). Both classes were well represented in cells grown at 39 degrees C. At this temperature their principal long chain bases were n-hexadeca-4-sphingenine and n-nonadeca-4-sphingenine. The major fatty acid of NCAEP from 39 degrees C-grown cells was palmitic acid and that of HCAEP was alpha-hydroxypalmitic acid. Cells grown at 15 degrees C contained NCAEP, but only traces of HCAEP. By analyzing the incorporation of [1-14C]palmitic acid into cells growing isothermally or shifted from 15 degrees C to 39 degrees C, we obtained evidence favoring a direct conversion of NCAEP to HCAEP. This conversion was blocked in cells grown at 15 degrees C, causing an accumulation of NCAEP. Tetrahymena is a useful model system for studying the poorly understood alpha-hydroxylation process that is of critical importance in myelination of animal nervous tissues.