Title : Identification of novel
fibronectin fragments detected specifically in juvenile urine
Abstract :
- Ugl-Y (young age-related urinary glycoprotein ) is an age-specific protein that we have previously identified in urine from healthy subjects under 18 years of age
- Isoelectric focusing analysis of Ugl-Y gives a set of three bands, Y1, Y2 and Y3, in the pH region around 3
- To determine the complete structure of Ugl-Y, purified Y1 and Y2 from pediatric urine were enzymatically cleaved, and the resulting peptides were analyzed by protein sequencing and/or MALDI-TOF MS. As a result, it was demonstrated that Y1 consists of 189 amino acid residues , and is identical to the region from A723 to R911 of fibronectin , whereas Y2 consists of 181 amino acid residues , and is identical to the region from A723 to R903
- Electrophoretic analysis of the lysate prepared from COS-7 cells transfected with Y1- or Y2-expressing vectors gave specific bands corresponding to Y1 or Y2, respectively, showing the validity of the sequences determined
- Partial purification of pediatric serum followed by western blotting revealed that Ugl-Y is derived from plasma
- Furthermore, Ugl-Y was generated by in vitro digestion of fibronectin by acid protease in extracts of osteoclast cells
- These findings suggest that Ugl-Y is probably produced by degradation of fibronectin comprising bone matrix during the process of vigorous bone resorption in children and adolescents
- This is the first report on the identification and characterization of juvenile-specific fibronectin fragments excreted into urine