Biomedical subjects
Publications and source records attributed to Karin Borge-Renberg.
A new genetic study has shown that the phagocytic ability of Drosophila blood cells, the hemocytes, may be important for the further induction of an antibacterial response in other tissues.
The peptidoglycan recognition protein PGRP-LC is a major activator of the imd/Relish pathway in the Drosophila immune response. Three transcripts are generated by alternative splicing of the complex PGRP-LC gene. The encoded transmembrane proteins share an identical intracellular part, but each has a separate extracellular PGRP-domain: x, y, or a. Here we show that two of these isoforms play unique roles in the response to different microorganisms. Using RNA interference in Drosophila mbn-2 cells, we found that PGRP-LCx is the only isoform required to mediate signals from Gram-positive bacteria and purified bacterial peptidoglycan. By contrast, the recognition of Gram-negative bacteria and bacterial lipopolysaccharide requires both PGRP-LCa and LCx. The third isoform, LCy, is expressed at lower levels and may be partially redundant. Two additional PGRP domains in the gene cluster, z and w, are both included in a single transcript of a separate gene, PGRP-LF. Suppression of this transcript does not block the response to any of the microorganisms tested.