title: Detection of ubiquityl-calmodulin conjugates with a novel high-molecular weight ubiquitylprotein-isopeptidase in rabbit tissues.
abstract: The selective degradation of many proteins in eukaryotic cells is carried out by the ubiquitin system. In this pathway, proteins are targeted for degradation by covalent ligation to ubiquitin, a highly conserved protein [1]. Ubiquitylated proteins were degraded by the 26S proteasome in an ATP-depended manner. The degradation of ubiquitylated proteins were controlled by isopeptidase cleavage. A well characterised system of ubiquitylation and deubiquitylation is the calmodulin system in vitro [2]. Detection of ubiquityl-calmodulin conjugtates in vivo have not been shown so far. In this article we discuss the detection of ubiquitin calmodulin conjugates in vivo by incubation with a novel high-molecular weight ubiquitylprotein-isopeptidase in rabbit tissues. Proteins with a molecular weight of ubiquityl-calmodulin conjugates could be detected in all organs tested. Incubation with ubiquitylprotein-isopeptidase showed clearly a decrease of ubiquitin calmodulin conjugates in vivo with an origination of unbounded ubiquitin. These results suggest that only few ubiquitin calmodulin conjugates exist in rabbit tissues.
authors.affiliation: Klinik für Anästhesiologie, Universitätsklinikum Düsseldorf, Germany. StephanUrs.Sixt@med.uni-duesseldorf.de
authors.forename: S U
authors.initials: SU
authors.lastname: Sixt
authors.forename: H P
authors.initials: HP
authors.lastname: Jennissen
authors.forename: M
authors.initials: M
authors.lastname: Winterhalter
authors.forename: M
authors.initials: M
authors.lastname: Laub
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002147:Calmodulin / Q000032:analysis; D019759:Carbon-Nitrogen Lyases / Q000737:chemistry*; D002852:Chromatography, Ion Exchange; D004912:Erythrocytes / Q000166:cytology / Q000201:enzymology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D018482:Muscle, Skeletal / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology; D010453:Peptide Synthases / Q000737:chemistry* / Q000302:isolation & purification; D011817:Rabbits; D012156:Reticulocytes / Q000166:cytology / Q000201:enzymology; D016415:Sequence Alignment; D014357:Trypsin; D025801:Ubiquitin / Q000032:analysis; D044764:Ubiquitin-Activating Enzymes; D044767:Ubiquitin-Protein Ligases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D000596:Amino Acids; D002147:Calmodulin; D025801:Ubiquitin; D044767:Ubiquitin-Protein Ligases; C059404:ubiquitin-calmodulin ligase; D014357:Trypsin; D019759:Carbon-Nitrogen Lyases; C034300:isopeptidase; D044764:Ubiquitin-Activating Enzymes; D010453:Peptide Synthases