Cytidylyltransferase-binding protein is identical to transcytosis-associated protein (TAP/p115) and enhances the lipid activation of cytidylyltransferase.

The Journal of Biological Chemistry
D A Feldman, P A Weinhold

Abstract

We previously identified a protein from rat liver that binds CTP:phosphocholine cytidylyltransferase (CT). We have now purified this protein (cytidylyltransferase-binding protein (CTBP)) from rat liver. The purification involved precipitation at pH 5 and extraction of the precipitate with buffer, followed by sequential chromatography on DEAE-Sepharose and butyl-agarose. Final purification was accomplished by either preparative electrophoresis or hydroxylapatite chromatography. Amino acid sequences from six peptides derived from pure CTBP matched sequences in transcytosis-associated protein (TAP) with 98% identity. Thus, CTBP was positively identified to be TAP. Purified CTBP increased the activity of purified CT measured with phosphatidylcholine (PC)/oleic acid. In the absence of PC/oleic acid, CTBP did not stimulate CT activity. Dilution of CT to reduce the Triton X-100 concentration produced a loss of CT activity. The lost activity was recovered by the addition of CTBP plus PC/oleic acid to the assay, but not by the addition of either PC/oleic acid or CTBP alone. Removal of CTBP from purified preparations by immunoprecipitation with CTBP antibodies eliminated the activation of CT. Both CT and CTBP were shown to bind to PC/ole...Continue Reading

References

Jan 1, 1992·Methods in Enzymology·P A Weinhold, D A Feldman
Jan 1, 1990·Progress in Lipid Research·C Kent
Jan 1, 1995·Annual Review of Biochemistry·C Kent
Jan 3, 1995·Proceedings of the National Academy of Sciences of the United States of America·H B SkinnerV A Bankaitis
Jan 17, 1995·Proceedings of the National Academy of Sciences of the United States of America·S K SappersteinM G Waters
Jan 17, 1995·Proceedings of the National Academy of Sciences of the United States of America·M BarrosoE Sztul
Feb 1, 1993·Protein Expression and Purification·J I MacDonald, C Kent
Jul 19, 1996·The Journal of Biological Chemistry·T P LevineG Warren

❮ Previous
Next ❯

Citations

Apr 24, 2001·Muscle & Nerve·E A Fon, R H Edwards
Jul 8, 1999·Current Opinion in Neurobiology·S M Bajjalieh
Apr 2, 1999·Biochimica Et Biophysica Acta·W TangI Tabas
Jan 1, 2003·Biochemical and Biophysical Research Communications·Seung Jin HanSeung Hwan Hong
Mar 17, 2017·Apoptosis : an International Journal on Programmed Cell Death·Mauro Degli EspostiMaurizio Sorice
Apr 20, 1999·Biochemical and Biophysical Research Communications·J M Clement, C Kent

❮ Previous
Next ❯

Related Concepts

Related Feeds

ASBMB Publications

The American Society for Biochemistry and Molecular Biology (ASBMB) includes the Journal of Biological Chemistry, Molecular & Cellular Proteomics, and the Journal of Lipid Research. Discover the latest research from ASBMB here.