PMID- 2765666
OWN - NLM
STAT- MEDLINE
DCOM- 19890925
LR  - 20210216
IS  - 0006-4971 (Print)
IS  - 0006-4971 (Linking)
VI  - 74
IP  - 4
DP  - 1989 Sep
TI  - Covalent modification of platelet proteins by palmitate.
PG  - 1339-47
AB  - Covalent attachment of fatty acid to proteins plays an important role in 
      association of certain proteins with hydrophobic membrane structures. In 
      platelets, the structure of many membrane glycoproteins (GPs) has been examined 
      in detail, but the question of fatty acid acylation of platelet proteins has not 
      been addressed. In this study, we wished to determine (a) whether platelet 
      proteins could be fatty acid acylated; and, if so, (b) whether these modified 
      proteins were present in isolated platelet membranes and cytoskeletal fractions; 
      and (c) if the pattern of fatty acid acylated proteins changed on stimulation of 
      the platelets with the agonist thrombin. We observed that in platelets allowed to 
      incorporate 3H-palmitate, a small percentage (1.37%) of radioactivity 
      incorporated into the cells became covalently bound to protein. Selective 
      cleavage of thioester, thioester plus O-ester, and amide-linked 3H-fatty acids 
      from proteins, and their subsequent analysis by high-performance liquid 
      chromatography (HPLC) indicated that the greatest part of 3H-fatty acid 
      covalently bound to protein was thioester-linked 3H-palmitate. By sodium dodecyl 
      sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and fluorography, at least 
      ten major radiolabeled proteins were detected. Activation of platelets by 
      thrombin greatly increased the quantity of 3H-palmitoylated proteins associated 
      with the cytoskeleton. Nearly all radiolabeled proteins were recovered in the 
      membrane fraction, indicating that these proteins are either integral or 
      peripheral membrane proteins or proteins tightly associated to membrane 
      constituents. Components of the GPIIb-IIIa complex were not palmitoylated. Thus, 
      platelet proteins are significantly modified posttranslationally by 3H-palmitate, 
      and incorporation of palmitoylated proteins into the cytoskeleton is a prominent 
      component of the platelet response to thrombin stimulation.
FAU - Muszbek, L
AU  - Muszbek L
AD  - Department of Pathology and Laboratory Medicine, University of Pennsylvania, 
      School of Medicine, Philadelphia 19104.
FAU - Laposata, M
AU  - Laposata M
LA  - eng
GR  - R01 DK37454/DK/NIDDK NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Blood
JT  - Blood
JID - 7603509
RN  - 0 (Cytoskeletal Proteins)
RN  - 0 (Hydroxylamines)
RN  - 0 (Palmitic Acids)
RN  - 0 (Platelet Membrane Glycoproteins)
RN  - 10028-17-8 (Tritium)
RN  - 2FP81O2L9Z (Hydroxylamine)
RN  - 2V16EO95H1 (Palmitic Acid)
RN  - 60-24-2 (Mercaptoethanol)
RN  - QTT17582CB (Hydrochloric Acid)
RN  - Y4S76JWI15 (Methanol)
SB  - IM
MH  - Acylation
MH  - Chromatography, High Pressure Liquid
MH  - Cytoskeletal Proteins/metabolism
MH  - Electrophoresis, Polyacrylamide Gel
MH  - Humans
MH  - Hydrochloric Acid
MH  - Hydrolysis
MH  - Hydroxylamine
MH  - Hydroxylamines
MH  - Mercaptoethanol
MH  - Methanol
MH  - Molecular Weight
MH  - Palmitic Acid
MH  - Palmitic Acids/metabolism/*pharmacology
MH  - Platelet Aggregation
MH  - Platelet Membrane Glycoproteins/*metabolism
MH  - Subcellular Fractions/analysis
MH  - Tritium
EDAT- 1989/09/01 00:00
MHDA- 1989/09/01 00:01
CRDT- 1989/09/01 00:00
PHST- 1989/09/01 00:00 [pubmed]
PHST- 1989/09/01 00:01 [medline]
PHST- 1989/09/01 00:00 [entrez]
AID - S0006-4971(20)82585-3 [pii]
PST - ppublish
SO  - Blood. 1989 Sep;74(4):1339-47.