Disease relevance of COPB2

• The overexpression of p102 in sarcomas and other neoplastic tissues suggests that this protein may be associated with the neoplastic state [1].
• However, the conjugate was not cytotoxic to p102 antigen negative rat fibrosarcoma SP-24 cells [2].
• We have previously shown that two proteins with apparent molecular masses of 91- and 102-kDa (p91 and p102, respectively) in human cytomegalovirus (HCMV)-infected cells are antigenically and structurally related to the major immediate-early (IE) 1 and 2 proteins (IE1p68 and IE2p80, respectively) of HCMV, respectively [3].
• Low levels of p102 were also expressed in membranes from some specimens of melanoma, lung and colorectal carcinoma, first trimester fetus, fat, lung and liver while skin specimens expressed slightly higher levels of antigen [1].

High impact information on COPB2

• Like beta-COP, p102 exists in a brefeldin A-sensitive association with Golgi membranes [4].
• The composition of this p102-containing protein complex resembles that of the Golgi coatomer complex, which constitutes the coat of non-clathrin coated vesicles [4].
• (i) Specific activity expressed relative to the amount of p102 was lower in Class 1 than in Class 2 PEPCs; (ii) reductive pyridoxylation of both p102 and p130 was inhibited by magnesium-phosphoenolpyruvate; and (iii) biphasic phosphoenolpyruvate binding kinetics were observed with Class 2 PEPCs [5].
• In the chlorophyte Selenastrum minutum, phosphoenolpyruvate carboxylase (PEPC) exists as two kinetically distinct classes of isoforms sharing the same 102-kDa catalytic subunit (p102) [5].
• SND p102 is a rat liver endoplasmic reticulum cholesterol ester hydrolase recently described as a member of a conserved family of transcriptional coactivators that promotes phospholipid secretion into lipoproteins when overexpressed in hepatocytes [6].

Chemical compound and disease context of COPB2

• Lectin affinity absorption indicated p102 was mannose containing glycoprotein, isoelectric point (pI) 4.7 and affinity constant of 2.3 x 10(9) M-1, with 5.9 x 10(5) binding sites per cultured human HT-1080 fibrosarcoma cell [1].

Anatomical context of COPB2

• RESULTS: The results from competition radioimmunoassay showed that binding of MAb 19-24 to SAA p102 on sarcoma cell membranes was inhibited by scFV1924 [7].
• High levels of p102 antigen were also found in all sarcoma, carcinoma cell lines and neonatal skin fibroblasts tested [1].
• Compared with hepatocytes with basal or attenuated SND p102 expression, they secreted approximately 45% and 80% more phospholipid in d<1.015 g/mL and 1.015<d<1.24 g/mL lipoproteins, respectively [8].

Associations of COPB2 with chemical compounds

• (iii) The steady-state levels of p91, but not p102, were remarkably decreased by treatment with proteasome inhibitor MG132, but coincubation with CH inhibited this decrease of p91 [3].
• Monoclonal antibody (MoAb) 19-24, which recognizes a cell surface sarcoma-associated antigen p102, was linked via a biotin-avidin-biotin bridge to adriamycin (ADR) [2].
• In this study, we extended the characterization of p91 and p102 and our results were as follows; (i) Lysine at amino acid position 450 in IE1p68 and at amino acid position 175 or 180 in IE2p80, to which SUMO-1 has been shown to be covalently linked, are required for production of p91 and p102, respectively [3].

Analytical, diagnostic and therapeutic context of COPB2

• Immunoblot, immunoprecipitation, and chemical cross-linking studies indicated that p102 physically interacts with the 130-kDa polypeptide (p130) in Class 2 PEPCs [5].
• Efficacy of a rice based oral rehydration solution containing human recombinant lactoferrin and lysosyme in children with acute diarrhea: p102 [9].
• The peptide NSARARADSCRI (p102) specifically bound anti-Par o 1 antibodies affinity purified from allergic patient sera or from rabbit anti-Par o 1 antiserum (ELISA) [10].
• MATERIALS AND METHODS: Monoclonal Antibody (MAb) 19-24 against the human sarcoma-associated antigen (SAA) p102 was previously characterized, and it demonstrated potential for sarcoma immunodiagnosis and immunotherapy [7].
• BACKGROUND: Monoclonal Antibody (MAb) 19-24 against the human sarcoma-associated antigen (SAA) p102 was previously characterized, and it demonstrated potential for sarcoma immunodiagnosis and immunotherapy [7].

References