Phosphatidylcholine stimulates the activity of UDP-Gal beta 1-4 galactosyltransferase in normal human kidney proximal tumour cells.

S. Chatterjee, N. Ghosh

Research output: Contribution to journalArticlepeer-review

Abstract

Effects of various lipid components of low density lipoproteins (LDL) and serine on the regulation of UDP-Gal-beta 1-4-galactosyltransferase (GalT-2) activity have been investigated in normal proximal tubular (PT) cells. Addition of exogenous serine (0.1-0.75 mM), cholesterol (0-200 micrograms/ml medium), linoleic acid and oleic acid (0.1-0.75 mM) for 4 hr at 37 degrees C did not suppress the activity of GalT-2 in PT cells. Similarly, incubation of cells with glucosylceramide and lactosylceramide (25-50 micrograms/ml medium) did not alter GalT-2 activity in cells as compared to control. In contrast, palmitic acid (0-0.75 mM), phosphatidylethanolamine and sphingomyelin (0-200 micrograms/ml) stimulated GalT-2 activity by 20-36% as compared to control. Incubation of PT cells with D-alpha-dipalmitoyl phosphatidylcholine (0-200 micrograms/ml medium) also stimulated the activity of GalT-2, maximum stimulation (200%) occurring with 25 micrograms phosphatidylcholine/ml medium. However, at a higher concentration (200 micrograms/ml), the stimulation of the activity of GalT-2 was in the order of 27% compared to control. Dioleylphosphatidylcholine did not alter GalT-2 activity in PT cells. Thus, it is concluded that (i) various lipid components, sphingosine and serine present in LDL are not involved in the LDL-mediated suppression of GalT-2 activity in normal PT cells, and (ii) stringent structural requirements in the phosphatidylcholine molecule are necessary to exert a time and concentration dependent stimulation of GalT-2 activity.

Original languageEnglish (US)
Pages (from-to)375-378
Number of pages4
JournalIndian journal of biochemistry & biophysics
Volume27
Issue number6
StatePublished - Dec 1990

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry

Fingerprint Dive into the research topics of 'Phosphatidylcholine stimulates the activity of UDP-Gal beta 1-4 galactosyltransferase in normal human kidney proximal tumour cells.'. Together they form a unique fingerprint.

Cite this