scholarly journals A vitamin-B2-sensing mechanism that regulates gut protease activity to impact animal’s food behavior and growth

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Bin Qi ◽  
Marina Kniazeva ◽  
Min Han
Keyword(s):  
Protease Activity ◽  
Regulatory Mechanisms ◽  
Protease Gene ◽  
Food Behavior ◽  
Nutrient Deficiencies ◽  
Vitamin B2 ◽  
Response Behavior ◽  
Food Uptake ◽  
Food Response ◽  
Specific Protease

To survive challenging environments, animals acquired the ability to evaluate food quality in the intestine and respond to nutrient deficiencies with changes in food-response behavior, metabolism and development. However, the regulatory mechanisms underlying intestinal sensing of specific nutrients, especially micronutrients such as vitamins, and the connections to downstream physiological responses in animals remain underexplored. We have established a system to analyze the intestinal response to vitamin B2 (VB2) deficiency in Caenorhabditis elegans, and demonstrated that VB2 level critically impacts food uptake and foraging behavior by regulating specific protease gene expression and intestinal protease activity. We show that this impact is mediated by TORC1 signaling through reading the FAD-dependent ATP level. Thus, our study in live animals uncovers a VB2-sensing/response pathway that regulates food-uptake, a mechanism by which a common signaling pathway translates a specific nutrient signal into physiological activities, and the importance of gut microbiota in supplying micronutrients to animals.

scholarly journals Maturation of the Arginine-Specific Proteases of Porphyromonas gingivalis W50 Is Dependent on a Functional prR2 Protease Gene

1998 ◽  
Vol 66 (4) ◽  
pp. 1594-1600 ◽  
Author(s):  
Joseph Aduse-Opoku ◽  
Minnie Rangarajan ◽  
Katherine A. Young ◽  
Michael A. Curtis
Keyword(s):  
Porphyromonas Gingivalis ◽  
Protease Activity ◽  
Parent Strain ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Chromatographic Behavior ◽  
Protease Gene ◽  
Insertional Inactivation ◽  
Specific Protease ◽  
Α Chain

ABSTRACT The prpR1 of Porphyromonas gingivalis codes for three distinct enzymes with specificity for arginyl peptide bonds termed RI, RIA, and RIB. These three isoforms comprise the majority of the extracellular, arginine-specific protease activity in P. gingivalis W50. RI is a heterodimer in which the catalytic α chain is noncovalently associated with a second chain involved in adherence phenomena. RIA and RIB are both monomeric species. RIA represents the free α chain, and RIB is a highly posttranslationally modified form of the α chain which is exclusively vesicle or membrane associated and migrates as a diffuse band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In previous studies, insertional inactivation of the prpR1 demonstrated that arginine-specific protease activity can also arise from a closely related second gene, prR2. In the present work, theprR2 was insertionally inactivated in P. gingivalis W50 in order to establish the contribution of this locus to the arginine-specific protease activity of this periodontal bacterium. Loss of prR2 function had several effects onprpR1-derived enzymes. First, the total Arg-X activity was reduced by approximately 50% relative to that of the parent strain. The reduction in total activity was a consequence of decreased concentrations of the monomeric enzymes derived from theprpR1, while the heterodimeric enzyme, RI, was unaffected by this mutation. Second, the chromatographic behavior of both the soluble and vesicle- or membrane-associated monomeric enzymes was radically different from the behavior of RIA and RIB from the parent strain. Finally, the vesicle- or membrane-associated enzyme in theprR2 mutant strain lacked the extensive posttranslational additions which are found on RIB in P. gingivalis W50. These data suggest that the product(s) of the prR2 plays a significant role in the maturation pathway of prpR1-derived enzymes, and this may contribute to the coconservation of these two genes in P. gingivalis.

scholarly journals Identification of bistable populations of Porphyromonas gingivalis that differ in epithelial cell invasion

Microbiology ◽  
2010 ◽  
Vol 156 (10) ◽  
pp. 3052-3064 ◽  
Author(s):  
S. Suwannakul ◽  
G. P. Stafford ◽  
S. A. Whawell ◽  
C. W. I. Douglas
Keyword(s):  
Epithelial Cells ◽  
Porphyromonas Gingivalis ◽  
Cell Invasion ◽  
Protease Activity ◽  
Periodontal Pathogen ◽  
Wild Type ◽  
Oral Epithelial Cells ◽  
Specific Protease ◽  
Oral Epithelial ◽  
First Time

Bistable populations of bacteria give rise to two or more subtypes that exhibit different phenotypes. We have explored whether the periodontal pathogen Porphyromonas gingivalis exhibits bistable invasive phenotypes. Using a modified cell invasion assay, we show for the first time that there are two distinct subtypes within a population of P. gingivalis strains NCTC 11834 and W50 that display differences in their ability to invade oral epithelial cells. The highly invasive subtype invades cells at 10–30-fold higher levels than the poorly invasive subtype and remains highly invasive for approximately 12–16 generations. Analysis of the gingipain activity of these subtypes revealed that the highly invasive type had reduced cell-associated arginine-specific protease activity. The role of Arg-gingipain activity in invasion was verified by enhancement of invasion by rgpAB mutations and by inclusion of an Arg-gingipain inhibitor in invasion assays using wild-type bacteria. In addition, a population of ΔrgpAB bacteria did not contain a hyperinvasive subtype. Screening of the protease activity of wild-type populations of both strains identified high and low protease subtypes which also showed a corresponding reduction or enhancement, respectively, of invasive capabilities. Microarray analysis of these bistable populations revealed a putative signature set of genes that includes oxidative stress resistance and iron transport genes, and which might be critical to invasion of or survival within epithelial cells.

scholarly journals Characterization of igaB, a Second Immunoglobulin A1 Protease Gene in Nontypeable Haemophilus influenzae

2006 ◽  
Vol 74 (10) ◽  
pp. 5860-5870 ◽  
Author(s):  
Matthew M. Fernaays ◽  
Alan J. Lesse ◽  
Xueya Cai ◽  
Timothy F. Murphy
Keyword(s):  
Haemophilus Influenzae ◽  
Virulence Factor ◽  
Protease Activity ◽  
Geographic Origin ◽  
Respiratory Pathogen ◽  
Chronic Obstructive ◽  
Protease Gene ◽  
Nontypeable Haemophilus Influenzae ◽  
Potential Virulence Factor ◽  
Iga1 Protease

ABSTRACT Nontypeable Haemophilus influenzae is an important respiratory pathogen, causing otitis media in children and lower respiratory tract infection in adults with chronic obstructive pulmonary disease (COPD). Immunoglobulin A1 (IgA1) protease is a well-described protein and potential virulence factor in this organism as well as other respiratory pathogens. IgA1 proteases cleave human IgA1, are involved in invasion, and display immunomodulatory effects. We have identified a second IgA1 protease gene, igaB, in H. influenzae that is present in addition to the previously described IgA1 protease gene, iga. Reverse transcriptase PCR and IgA1 protease assays indicated that the gene is transcribed, expressed, and enzymatically active in H. influenzae. The product of this gene is a type 2 IgA1 protease with homology to the iga gene of Neisseria species. Mutants that were deficient in iga, igaB, and both genes were constructed in H. influenzae strain 11P6H, a strain isolated from a patient with COPD who was experiencing an exacerbation. Analysis of these mutants indicated that igaB is the primary mediator of IgA1 protease activity in this strain. IgA1 protease activity assays on 20 clinical isolates indicated that the igaB gene is associated with increased levels of IgA1 protease activity. Approximately one-third of 297 strains of H. influenzae of diverse clinical and geographic origin contained igaB. Significant differences in the prevalence of igaB were observed among isolates from different sites of isolation (sputum > middle ear > nasopharynx). These data support the hypothesis that the newly discovered igaB gene is a potential virulence factor in nontypeable H. influenzae.

scholarly journals Optimasi Waktu Inkubasi Lactobacillus rhamnosus SKG 34 Dalam Produksi Enzim Penggumpal Susu

2020 ◽  
Vol 9 (2) ◽  
pp. 108
Author(s):  
Wulandari Setiadarma ◽  
Dewa Gede Mayun Permana ◽  
Komang Ayu Nocianitri
Keyword(s):  
Incubation Time ◽  
Protease Activity ◽  
Block Design ◽  
Lactobacillus Rhamnosus ◽  
Duncan Multiple Range Test ◽  
Milk Clotting ◽  
Randomized Block Design ◽  
Milk Clotting Enzyme ◽  
Specific Protease ◽  
Range Test

This study aims to determine the effect of incubation time on milk clotting enzyme (MCE) activity produced by L. rhamnosus SKG 34 and determine the optimum incubation time to produce the highest its activity. This study used a randomized block design (RBD) with incubation time as a treatment consisting of 8 levels, that were 6 hours, 12 hours, 18 hours, 24 hours, 30 hours, 36 hours, 42 hours, and 48 hours. Data were analyzed with Variance Analysis (ANOVA) than followed by Duncan Multiple Range Test (DMRT). The analyzed were repeated 3 times resulting in 24 experimental units. The results showed that the incubation time significantly affected protease activity, MCE activity, specific protease activity and ratio of MCE to protease but did not affect the total LAB. The optimum incubation time of L. rhamnosus SKG 34 is 12 hours with total LAB 1.83 x 109 CFU/ml and protease activity 180.67 U/ml, MCE activity 595.06 SU, protease spesific activity 73.149 U/mg and ratio of MCE to protease 3.29 SU/U. Keywords : incubation time, Enzyme protease, Lactobacillus rhamnosus SKG 34, Milk clotting enzyme.

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