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The hmp chemotaxis cluster regulates gliding in the filamentous cyanobacterium Nostoc punctiforme
Loralyn M Cozy1, Sean M Callahan
1Department of Microbiology, University of Hawaii, Honolulu, HI, 96822, USA.
Molecular Microbiology
|March 5, 2014
Summary
Researchers identified a key genetic region, the hormogonia motility and polysaccharide (hmp) locus, essential for gliding movement in the cyanobacterium Nostoc punctiforme. This discovery advances understanding of bacterial motility in complex organisms.
Area of Science:
- Microbiology
- Bacterial Motility
- Cyanobacteria Research
Background:
- Many bacteria exhibit gliding motility, a flagella- and pili-independent form of movement over surfaces.
- Nostoc punctiforme, a cyanobacterium, forms specialized gliding filaments called hormogonia, but the mechanism of their motility remains unclear.
Purpose of the Study:
- To characterize the mechanism of hormogonia gliding motility in Nostoc punctiforme.
- To identify and analyze the genetic components regulating this specialized movement.
Main Methods:
- Genetic analysis of the hormogonia motility and polysaccharide (hmp) locus.
- Protein localization studies within hormogonia cells.
- Biochemical assays to investigate protein phosphorylation and phosphotransfer.
Main Results:
- The hmp locus, containing genes homologous to chemotaxis systems, is crucial for gliding motility.
- Most genes within the hmp locus are required for movement, with encoded proteins forming ring-like structures at cell junctions.
- Key proteins HmpE (a CheA homolog) and HmpB (a CheY homolog) participate in a phosphorylation-dependent signaling pathway.
Conclusions:
- The hmp locus is a significant regulator of gliding motility in Nostoc punctiforme.
- Nostoc punctiforme hormogonia serve as a valuable model for studying gliding in complex, multicellular bacteria.
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