PRB3 null mutations result in absence of the proline-rich glycoprotein Gl and abolish Fusobacterium nucleatum interactions with saliva in vitro.

摘要: The glycosylated proline-rich glycoprotein (Gl or PRG), a product of the PRB3 gene, is major constituent human parotid saliva. Important functions proposed for Gl include acting as bacterial receptor. proteins several subjects were typed by two polyacrylamide gel electrophoresis (PAGE) systems: acid-lactate PAGE followed staining with periodic acid-Schiff reagent and sodium dodecyl sulfate-PAGE electrophoretic transfer amido black concanavalin A. results showed one subject who apparently lacked Gl. four exons, including splice junctions, both alleles this completely sequenced. Unexpressed (null) mutations detected an identical C nucleotide insertion in same coding region exon 3 alleles. This leads to frameshift premature termination codon that probably markedly reduced absent gene expression. We then used nitrocellulose blot overlay assay receptor activity saliva from PRB3null subject. No interactions Fusobacterium nucleatum, shown previously interact selectively Gl, detected. Together, these suggest does not express consequences altered ability bacterium known colonize oral cavity.