Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2004-12-6
pubmed:abstractText
Pseudoachondroplasia (PSACH) is an autosomal dominant disease that mainly affects cartilage, resulting in skeletal dysplasias and early onset osteoarthritis. PSACH is caused by mutations in the cartilage oligomeric matrix protein (COMP) gene. PSACH chondrocytes accumulate unique COMP-containing lamellar structures in an expanded rough endoplasmic reticulum (rER). Although COMP is also present in tendon extracellular matrix (ECM), it does not accumulate in PSACH tendon cells, suggesting the disease involves a chondrocyte-specific trafficking problem. To investigate putative cell-specific trafficking differences, we generated a cell culture model utilizing expression of the common DeltaD469 COMP mutation. In rat chondrosarcoma (RCS) cells, we find delayed secretion and ER accumulation of DeltaD469 COMP, paralleling the altered trafficking defect in PSACH chondrocytes. Non-chondrocytic COS-1 cells, in contrast, efficiently trafficked and secreted both mutant and wild-type COMP. In chondrocytic cells, expression of DeltaD469 COMP led to ER accumulation of type IX collagen, but did not affect aggrecan trafficking. Endogenous rat COMP accumulated in the ER along with expressed DeltaD469 COMP in a stably expressing RCS clone, consistent with the dominant negative effect of PSACH. When these stably expressing cells were cultured to promote ECM deposition, the small amount of secreted mutant COMP disrupted assembly of the normal fibrillar meshwork and caused irregular aggregates of COMP and type IX collagen to form. Thus, in a new model that reflects the cellular pathology of PSACH, we establish trafficking differences for mutant COMP in chondrocytic and non-chondrocytic cells and demonstrate that mutant COMP interferes with assembly of a normal ECM.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0945-053X
pubmed:author
pubmed:issnType
Print
pubmed:volume
23
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
433-44
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:15579310-Achondroplasia, pubmed-meshheading:15579310-Aggrecans, pubmed-meshheading:15579310-Animals, pubmed-meshheading:15579310-Blotting, Western, pubmed-meshheading:15579310-COS Cells, pubmed-meshheading:15579310-Cell Culture Techniques, pubmed-meshheading:15579310-Chondrocytes, pubmed-meshheading:15579310-Chondrosarcoma, pubmed-meshheading:15579310-Collagen, pubmed-meshheading:15579310-DNA, pubmed-meshheading:15579310-Endoplasmic Reticulum, pubmed-meshheading:15579310-Extracellular Matrix Proteins, pubmed-meshheading:15579310-Glycoproteins, pubmed-meshheading:15579310-Golgi Apparatus, pubmed-meshheading:15579310-Humans, pubmed-meshheading:15579310-Immunoprecipitation, pubmed-meshheading:15579310-Lectins, C-Type, pubmed-meshheading:15579310-Microscopy, Fluorescence, pubmed-meshheading:15579310-Mutation, pubmed-meshheading:15579310-Proteoglycans, pubmed-meshheading:15579310-Rats, pubmed-meshheading:15579310-Time Factors
pubmed:year
2004
pubmed:articleTitle
Cell-type specific trafficking of expressed mutant COMP in a cell culture model for PSACH.
pubmed:affiliation
Department of Cell Biology and Anatomy, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't