Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2002-6-18
pubmed:abstractText
Fatty acylation of proteins on cysteine residues is a common post-translational modification that plays roles in protein-membrane and protein-protein interactions. Recently, we described a lysosomal palmitoyl-protein thioesterase that removes long-chain fatty acids from lipid-modified cysteine residues in proteins. Deficiency in palmitoyl-protein thioesterase results in a human lysosomal storage disorder, infantile neuronal ceroid lipofuscinosis (INCL), which primarily affects the central nervous system. The pathological hallmark of the disorder is the accumulation of granular osmiophilic deposits (GROD) that resemble lipofuscin, or aging pigment. In previous work, we have shown that [35S]cysteine-labeled lipid thioesters derived from fatty acylated proteins accumulate in cultured cells derived from palmitoyl-protein thioesterase-deficient patients. In the present work, we show that the lipid cysteine thioesters accumulate in the lysosomal fraction, and we further show that the appearance of these compounds in the organic phase is blocked by inhibitors of lysosomal proteolysis, demonstrating through biochemical means the lysosomal nature of the site of palmitoyl-protein thioesterase action. Furthermore, substrates for palmitoyl-protein thioesterase accumulate even in normal cells after leupeptin or chloroquine treatment. This was demonstrated by subjecting extracts of treated cells to exhaustive proteolysis to release protein-bound cysteine lipid for analysis. Cysteamine, a lysosomotropic drug recently proposed for the treatment of INCL, was found to have effects similar to leupeptin and chloroquine, suggesting that its mechanism of action may be more complex than previously understood.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
1583
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
35-44
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
The effects of lysosomotropic agents on normal and INCL cells provide further evidence for the lysosomal nature of palmitoyl-protein thioesterase function.
pubmed:affiliation
Department of Internal Medicine and the Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas 75390-8593, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't