Myxococcus xanthus encodes an ATP-dependent protease which is required for developmental gene transcription and intercellular signaling

Gill, Richard; Karlok, M; Benton, David

doi:10.1128/jb.175.14.4538-4544.1993

Cited by 73 publications

(69 citation statements)

References 21 publications

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“…The protein encoded by bsg is homologous to the bacterial Lon protease and is essential for expression of early developmental genes (39,40). Of particular interest is the role of poly P in the activation of Lon when an E. coli culture is switched from a rich medium to a minimal medium (6,7).…”

Section: Discussionmentioning

confidence: 99%

Inorganic polyphosphate in the social life of Myxococcus xanthus : Motility, development, and predation

Zhang

Rao

Shiba

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

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Inorganic polyphosphate (poly P), a polymer of tens or hundreds of phosphate residues linked by high-energy, ATP-like bonds, is found in all organisms and performs a wide variety of functions. Myxococcus xanthus, a social bacterium that feeds on other bacteria and forms fruiting bodies and spores, depends on poly P for motility, development, and nutritional predation. Two poly P metabolizing enzymes were studied in M. xanthus: poly P kinase 1, which synthesizes poly P reversibly from ATP, and poly P:AMP phosphotransferase, which uses poly P as a donor to also reversibly convert AMP to ADP. The null mutant of ppk1 is defective in social motility, overproduces pilin protein on the cell surface, is delayed in fruiting body formation, produces fewer spores, is delayed in germination, and forms far smaller plaques on a lawn of Klebsiella aerogenes. The pap mutant is also impaired in social motility, but shows only slightly reduced abilities in development and predation.

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Section: Discussionmentioning

confidence: 99%

Inorganic polyphosphate in the social life of Myxococcus xanthus : Motility, development, and predation

Zhang

Rao

Shiba

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

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“…The phenotype of yeast strain lacking Lon is the presence of large deletions within the mtDNA (22,27), suggesting that Lon is required for the stability and expression of the mitochondrial genome. Moreover, in vivo studies in bacteria and yeast suggest that Lon is involved in controlling gene expression, either by regulating the levels of transcription factors or by influencing the stability of mRNA transcripts (28,29). Recently, Liu et al (30) reported that ATP inhibits the binding of human Lon to DNA or RNA.…”

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confidence: 99%

Functional Domains of Brevibacillus thermoruber Lon Protease for Oligomerization and DNA Binding

Lee

Hsu

2004

Journal of Biological Chemistry

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Lon protease is a multifunctional enzyme, and its functions include the degradation of damaged proteins and naturally short lived proteins, ATPase and chaperonelike activities, as well as DNA binding. A thermostable Lon protease from Brevibacillus thermoruber WR-249 (BtLon) has been cloned and characterized with an N-terminal domain, a central ATPase domain that includes a sensor and substrate discrimination (SSD) domain, and a C-terminal protease domain. Here we present a detailed structure-function characterization of Bt-Lon, not only dissecting the individual roles of Bt-Lon domains in oligomerization, catalytic activities, chaperone-like activity, and DNA binding activity but also describing the nature of oligomerization. Seven truncated mutants of Bt-Lon were designed, expressed, and purified. Our results show that the N-terminal domain is essential for oligomerization. The truncation of the N-terminal domain resulted in the failure of oligomerization and led to the inactivation of proteolytic, ATPase, and chaperone-like activities but retained the DNA binding activity, suggesting that oligomerization of Bt-Lon is a prerequisite for its catalytic and chaperone-like activities. We further found that the SSD is involved in DNA binding based on gel mobility shift assays. On the other hand, the oligomerization of Bt-Lon proceeds through a dimer 7 tetramer 7 hexamer assembly model revealed by chemical cross-linking experiments. The results also showed that hydrophobic interactions may play important roles in the dimerization of Bt-Lon, and ionic interactions are mainly responsible for the assembly of hexamers.Lon protease (La), the first ATP-dependent protease purified from Escherichia coli (1, 2), is a member of the ATPases associated with diverse cellular activities (AAA ϩ ) 1 superfamily (3).Lon consists of a variable N-terminal domain, a central ATPase domain, and a C-terminal protease domain on a single polypeptide (4, 5). The N-terminal domain with its still obscure function contains a potential coiled coil region built from ␣-helices and is proposed to be involved in binding and recognition of substrate proteins (5, 6). Lon is active as a homo-oligomer (7-10), which is distinct from other ATP-dependent proteases, Clp/HSP100 proteins, forming a hetero-oligomer. Nevertheless, the oligomeric state of Lon is still vague. Lon behaves as a tetramer or an octamer in E. coli (7), as a tetramer to a hexamer in Mycobacterium (5, 10), and as a hexamer or a heptamer in yeast mitochondria (8, 9). More recently, we have shown that Brevibacillus thermoruber Lon (Bt-Lon) is a hexameric structure (11). On the other hand, Clp/HSP100 proteins form a hexameric structure in the presence of ATP (12-15). Furthermore, the N-terminal domain of many Clp/HSP100 proteins, which is involved in binding of protein substrates (16 -18), is not necessary for oligomerization (17)(18)(19). By analogy with Clp/HSP100 proteins, it is quite reasonable to predict that the regulation of oligomerization of Lon may occur through an N-terminal doma...

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“…In vivo, E. coli Lon protease specifically degrades several short-lived proteins, including the cell division inhibitor SulA and a transcriptional regulator, RcsA (7). Lon homologs have been identified in both Gramnegative and Gram-positive bacteria; in Myxococcus, one Lon-like protein has a role in development of fruiting bodies (8)(9)(10)(11). E. coli also possesses a second ATP-dependent protease, Clp, which is a multicomponent protease that degrades a variety of specific proteins as well as abnormal proteins (1, 12, 13).…”

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confidence: 99%

A human mitochondrial ATP-dependent protease that is highly homologous to bacterial Lon protease.

Wang

Gottesman²,

Willingham³

et al. 1993

Proc. Natl. Acad. Sci. U.S.A.

179

124

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We have cloned a human ATP-dependent protease that is highly homologous to members of the bacterial Lon protease family. The cloned gene encodes a protein of 963 amino acids with a calculated molecular mass of 106 kDa, slightly higher than that observed by Western blotting the protein from human tissues and ceil lines (100 kDa). A single species of mRNA was found for this Lon protease in all human tissues examined. The protease is encoded in the nucleus, and the amino-terminal portion of the protein sequence contains a potential mitochondrial targeting presequence. Immunofluorescence microscopy suggested a predominantly mitochondrial localization for the Lon protease in cultured human ceils. A truncated LON gene, in which translation was initiated at Metll8ofthe coding sequence, was expressed in Escherichia coli and produced a protease that degraded a-casein in vitro in an ATP-dependent manner and had other properties similar to E. col Lon protease.

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Myxococcus xanthus encodes an ATP-dependent protease which is required for developmental gene transcription and intercellular signaling

Cited by 73 publications

References 21 publications

Inorganic polyphosphate in the social life of Myxococcus xanthus : Motility, development, and predation

Inorganic polyphosphate in the social life of Myxococcus xanthus : Motility, development, and predation

Functional Domains of Brevibacillus thermoruber Lon Protease for Oligomerization and DNA Binding

A human mitochondrial ATP-dependent protease that is highly homologous to bacterial Lon protease.

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