title: Transient expression of megakaryocyte-derived protein immunoreactive with an antiserum to cartilage oligomeric matrix protein in developing rat liver.
abstract: We analyzed a megakaryocyte-derived protein immunoreactive with an antiserum to cartilage oligomeric matrix protein (COMP) in the developing rat liver. Staining with the anti-COMP antiserum in the developing rat liver increased during embryogenesis, and was strongest in the livers of 17-day-old embryos. However, staining in the liver was not detected at eight days after birth or thereafter. The stained cells were found to be megakaryocytes. We partially purified the protein showing cross-reaction with the antiserum to COMP from a megakaryocyte-rich cells fraction in 17-day-old embrionic rat livers. The molecular weight of this protein (approximately 95 kDa) was close to the molecular weight of COMP (105 kDa). Amplification of an RT-PCR fragment (225 bp) corresponding to part of COMP mRNA was detected in cartilage, but not in megakaryocytes of fetal liver or bone marrow. Based on these results, the fetal rat liver megakaryocyte-derived protein that reacted with the antiserum against COMP was thought to contain a common epitope with COMP from cartilage, but to be a different protein from COMP.
authors.affiliation: Department of Clinical and Biomedical Sciences, Showa Pharmaceutical University, Tokyo, 194-8543, Japan. onodera@ac.shoyaku.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Onodera
authors.forename: Y
authors.initials: Y
authors.lastname: Tonozuka
authors.forename: S
authors.initials: S
authors.lastname: Tashiro
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D001853:Bone Marrow / Q000378:metabolism; D064236:Cartilage Oligomeric Matrix Protein; D002358:Cartilage, Articular / Q000196:embryology / Q000378:metabolism; D002417:Cattle; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008099:Liver / Q000196:embryology / Q000378:metabolism*; D064235:Matrilin Proteins; D008533:Megakaryocytes / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
chemical_list: D064236:Cartilage Oligomeric Matrix Protein; D016326:Extracellular Matrix Proteins; D006023:Glycoproteins; C577540:Matn1 protein, mouse; D064235:Matrilin Proteins; C577553:TSP5 protein, human; D000110:Acetylcholinesterase