Linked Life Data

12019270

Source:http://linkedlifedata.com/resource/pubmed/id/12019270

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
31
pubmed:dateCreated
2002-7-29
pubmed:abstractText
Recent studies have led to the identification of a group of genes required for normal biogenesis of lysosome-related organelles such as melanosomes and platelet-dense granules. Two of these genes, which are defective in the pallid and muted mutant mouse strains, encode small, coiled-coil-forming proteins that display no homology to each other or to any known protein. We report that these two proteins, pallidin and muted, are components of a novel protein complex. We raised antibodies that allow for detection of pallidin from a wide variety of mammalian cells. Endogenous pallidin was distributed in both soluble and peripheral membrane protein fractions. Size-exclusion chromatography and sedimentation velocity analyses indicated that the bulk of cytosolic pallidin is a component of an asymmetric protein complex with a molecular mass of approximately 200 kDa. We named this complex BLOC-1 (for biogenesis of lysosome-related organelles complex 1). Steady-state pallidin protein levels were reduced in fibroblasts derived from muted and reduced pigmentation mice, suggesting that the genes defective in these two mutant strains could encode components of BLOC-1 that are required for pallidin stability. Co-immunoprecipitation and immunodepletion experiments using an antibody to muted confirmed that this protein is a subunit of BLOC-1. Yeast two-hybrid analyses revealed that pallidin is capable of self-association through a region that contains its two coiled-coil forming domains. Unlike AP-3-deficient pearl fibroblasts, which display defects in intracellular zinc storage, zinc distribution was not noticeably affected in pallid or muted fibroblasts. Interestingly, immunofluorescence and in vitro binding experiments demonstrated that pallidin/BLOC-1 is able to associate with actin filaments. We propose that BLOC-1 mediates the biogenesis of lysosome-related organelles by a mechanism that may involve self-assembly and interaction with the actin cytoskeleton.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
28191-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
BLOC-1, a novel complex containing the pallidin and muted proteins involved in the biogenesis of melanosomes and platelet-dense granules.
pubmed:affiliation
Department of Human Genetics, UCLA School of Medicine, Los Angeles, California 90095, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.