Document 0677
 DOCN  M9550677
 TI    Inhibition of protein kinase C by a synthetic peptide corresponding to
       cytoplasmic domain residues 828-848 of the human immunodeficiency virus
       type 1 envelope glycoprotein.
 DT    9505
 AU    Ward NE; Gravitt KR; O'Brian CA; Department of Cell Biology, University
       of Texas M.D. Anderson; Cancer Center, Houston 77030.
 SO    Cancer Lett. 1995 Jan 6;88(1):37-40. Unique Identifier : AIDSLINE
       MED/95153645
 AB    This report describes the inhibition of protein kinase C (PKC) by a
       synthetic peptide corresponding to a viral sequence expressed in
       mammalian cells. The peptide corresponds to cytoplasmic domain residues
       828-848 of the human immunodeficiency virus type 1 (HIV-1) envelope
       glycoprotein (gp41), and it inhibits Ca(2+)- and phosphatidylserine
       (PS)-dependent phosphorylation of synthetic peptide substrates and
       histone by purified PKC with IC50 values ranging from 9 to 32 microM.
       Although previously described pKC-inhibitory synthetic peptides
       corresponding to sequences expressed in mammalian cells are also
       effective against the phosphorylation of synthetic peptide substrates,
       they fail to affect PKC-catalysed phosphorylation of potent protein
       substrates such as histone. This may limit their usefulness as
       inhibitors of PKC-catalysed protein phosphorylation in cellular systems.
       PKC activation is a major contributing factor in multidrug resistance
       (MDR) in cancer. Our observation that the synthetic peptide
       gp41(828-848) inhibits pKC-catalysed phosphorylation of a protein
       substrate suggests the potential value of expressing the viral sequence
       gp41(828-848) in cancer cells as a novel in vitro model system of MDR
       reversal.
 DE    Amino Acid Sequence  Animal  Brain/ENZYMOLOGY  Calcium/PHARMACOLOGY  HIV
       Envelope Protein gp41/CHEMISTRY/*PHARMACOLOGY  In Vitro  Molecular
       Sequence Data  Peptides/PHARMACOLOGY  Phosphatidylserines/PHARMACOLOGY
       Protein Kinase C/*ANTAGONISTS & INHIB  Rats  Support, Non-U.S. Gov't
       Support, U.S. Gov't, P.H.S.  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).