1.Influence of eucalyptol on biological effects of spleen cold and spleen heat syndromes in rats and mechanism of regulating spleen channel with its warm nature based on TRP ion channel.
Xing-Yu ZHAO ; Yi LI ; Xiao-Fang WU ; Qi ZHANG ; Lin-Ze LI ; Yin-Ming ZHAO ; Chun WANG ; Jian-Jun ZHANG ; Lin-Yuan WANG
China Journal of Chinese Materia Medica 2025;50(8):2022-2031
This paper aims to investigate the influence of eucalyptol on the biological effects of spleen cold and spleen heat syndromes in rats and its regulation of transient receptor potential vanilloid 1(TRPV1), transient receptor potential melastatin 8(TRPM8), and uncoupling protein 1(UCP1), so as to explore the cold-heat properties of eucalyptol. Rats were randomly divided into groups as follows: blank group, spleen cold syndrome model group, spleen cold syndrome+Atractylodis Rhizoma group, spleen cold syndrome + low-dose eucalyptol group, and spleen cold syndrome+high-dose eucalyptol group, as well as blank group, spleen heat syndrome model group, spleen heat syndrome+Coptidis Rhizoma group, spleen heat syndrome + low-dose eucalyptol group, and spleen heat syndrome + high-dose eucalyptol group. Spleen cold and spleen heat syndromes were induced by disorders of hunger and satiety combined with bitter cold drugs, as well as a high-fat diet combined with liquor. Except for the blank and model groups, the other groups were administered once a day during the modeling process for 14 consecutive days. The general condition and body weight of rats in each group were observed, and the histopathological morphology of the gastric antrum and small intestine was observed by hematoxylin-eosin(HE) staining. The contents of cyclic adenosine monophosphate(cAMP), cyclic guanosine monophosphate(cGMP), triiodothyronine(T3), thyroxine(T4), Na~+-K~+-ATPase, total cholesterol(TC), triglyceride(TG), gastrin(GAS), motilin(MTL), D-xylose, and other related indices were detected in rats. The expression levels of TRPV1, TRPM8, and UCP1 in small intestine tissue of rats with spleen cold syndrome were detected. The results showed that eucalyptol had a certain degree of improvement in the overall state and body weight of rats with spleen cold syndrome. Compared with the spleen cold syndrome model group, high-dose eucalyptol significantly increased the levels of serum cAMP, cAMP/cGMP, TG, and TC in rats with spleen cold syndrome(P<0.05, P<0.01), decreased the content of cGMP, and significantly elevated the levels of gastrointestinal function-related indicators GAS, MTL, and D-xylose(P<0.05, P<0.01). Low-dose eucalyptol significantly increased the level of cAMP/cGMP in the serum and Na~+-K~+-ATPase levels in hepatic tissue(P<0.05, P<0.01), and significantly increased the levels of GAS and D-xylose(P<0.01). Eucalyptol showed similar effects to Atractylodis Rhizoma with a warm nature on rats with spleen cold syndrome. Compared with the spleen heat syndrome model group, the high-dose and low-dose eucalyptol groups showed a trend of increase in gastrointestinal indicators, with no significant changes in other indicators. In addition, high-dose eucalyptol increased the expression of TRPV1 and UCP1 and decreased the expression of TRPM8 in the small intestine tissue of rats with spleen cold syndrome. Eucalyptol could affect the cyclic nucleotide and material energy metabolism levels of rats with spleen cold syndrome and had a certain improvement effect on their gastrointestinal digestion and absorption function, thereby improving spleen cold syndrome. Eucalyptol had no significant improvement effect on rats with spleen heat syndrome, suggesting that eucalyptol may have a warm nature and regulate spleen meridians. It is speculated that eucalyptol may exhibit its medicinal properties by activating the TRPV1 pathway, promoting the expression of UCP1, and inhibiting the TRPM8 channel.
Animals
;
Rats
;
Spleen/metabolism*
;
Male
;
TRPV Cation Channels/genetics*
;
Rats, Sprague-Dawley
;
Eucalyptol/administration & dosage*
;
TRPM Cation Channels/genetics*
;
Uncoupling Protein 1/genetics*
;
Humans
;
Drugs, Chinese Herbal/administration & dosage*
;
Cold Temperature
;
Cyclic GMP/metabolism*
2.Medicinal properties and mechanisms of p-cymene with mild and warm nature based on deficiency-cold and deficiency-heat syndrome models.
Xiao-Fang WU ; Yi LI ; Xing-Yu ZHAO ; Lin-Ze LI ; Qi ZHANG ; Yin-Ming ZHAO ; Ying-Li ZHU ; Chun WANG ; Jian-Jun ZHANG ; Lin-Yuan WANG
China Journal of Chinese Materia Medica 2025;50(8):2032-2040
This paper aims to study the effect of p-cymene on mice with deficiency-cold syndrome induced by hydrocortisone and deficiency-heat syndrome induced by dexamethasone and explore the medicinal properties and mechanism of p-cymene with mild and warm nature based on the dominant characteristics of the two-way applicable conditions of mild drugs. A total of 80 KM mice were randomly divided into blank group, deficiency-cold syndrome model group, deficiency-cold syndrome + ginseng group, and deficiency-cold syndrome + low-dose and high-dose p-cymene groups, as well as blank group, deficiency-heat syndrome model group, deficiency-heat syndrome + American ginseng group, and deficiency-heat syndrome + low-dose and high-dose p-cymene groups. Hydrocortisone and dexamethasone solution were intragastrically administered for 14 consecutive days to prepare deficiency-cold syndrome and deficiency-heat syndrome models. Except for the blank group and the model group intragastrically administered with normal saline, the other groups were intragastrically administrated with drugs for 14 days. The levels of cyclic adenosine monophosphate(cAMP), cyclic guanosine monophosphate(cGMP), triiodothyronine(T3), thyroxine(T4), total cholesterol(TC), triglyceride(TG), immunoglobin G(IgG), and immunoglobin M(IgM) in serum, as well as the activity of Na~+-K~+-ATPase in liver tissue were detected. The expression of transient receptor potential melastatin 8(TRPM8), transient receptor potential vanilloid 1(TRPV1), and uncoupling protein 1(UCP1) in brown adipose tissue of deficiency-cold syndrome model after intervention with p-cymene was studied. The results showed that p-cymene could effectively improve the levels of cAMP, cAMP/cGMP, TC, IgM, and IgG in serum and the activity of Na~+-K~+-ATPase in liver tissue of mice with deficiency-cold syndrome and reduce the content of cGMP. The effects on T3, T4, and TG were not statistically significant. At the same time, p-cymene could reduce the levels of cAMP, cAMP/cGMP, and T4 in serum and the activity of Na~+-K~+-ATPase in liver tissue of mice with deficiency-cold syndrome and increase the levels of cGMP, IgM, and IgG, and it had no effect on T3, TC, and TG. In addition, p-cymene could up-regulate the expression of TRPV1 and UCP1 in brown fat of mice with deficiency-cold syndrome and down-regulate the expression of TRPM8. In summary, p-cymene could significantly regulate the syndrome indexes of mice with deficiency-cold syndrome, and some indexes of mice with deficiency-heat syndrome could be improved, but the effects on lipid metabolism and energy metabolism indexes were not obvious, indicating that the regulation effect of p-cymene on deficiency-cold syndrome model was more prominent and that the medicinal properties of p-cymene were mild and warm. The regulation of TRPV1/TRPM8/UCP1 channel expression may be the molecular biological mechanism of p-cymene with mild and warm nature affecting the energy metabolism of the body.
Animals
;
Cymenes
;
Mice
;
Drugs, Chinese Herbal/administration & dosage*
;
Male
;
Disease Models, Animal
;
Humans
;
Cyclic AMP/metabolism*
;
Monoterpenes/administration & dosage*
;
Liver/metabolism*
;
Cyclic GMP/metabolism*
;
TRPV Cation Channels/genetics*
;
Uncoupling Protein 1/genetics*
3.Modulation of SIRT1 expression improves erectile function in aged rats.
Wen YU ; Jing WANG ; Yu-Tian DAI ; Bin WANG ; Yang XU ; Qing-Qiang GAO ; Zhi-Peng XU
Asian Journal of Andrology 2022;24(6):666-670
Silent information regulator 2-related enzyme 1 (SIRT1) is an aging-related protein activated with aging. Herein, we evaluated the role of SIRT1 in aging-related erectile dysfunction. The expression of SIRT1 was modulated in aged Sprague-Dawley rats following intragastric administration of resveratrol (Res; 5 mg kg-1), niacinamide (NAM; 500 mg kg-1) or Res (5 mg kg-1) + tadalafil (Tad; phosphodiesterase-5 [PDE5] inhibitor; 5 mg kg-1) for 8 weeks. Then, we determined erectile function by the ratio of intracavernosal pressure (ICP)/mean systemic arterial pressure (MAP). Cavernosal tissues were extracted to evaluate histological changes, cell apoptosis, nitric oxide (NO)/cyclic guanosine monophosphate (cGMP), the superoxide dismutase (SOD)/3,4-methylenedioxyamphetamine (MDA) level, and the expression of SIRT1, p53, and forkhead box O3 (FOXO3a) using immunohistochemistry, terminal deoxynucleotidyl transferase (TdT)-mediated 2'-deoxyuridine 5'-triphosphate (dUTP) nick-end labeling (TUNEL), enzyme-linked immunosorbent assays, and western blot analysis. Compared with the control, Res treatment significantly improved erectile function, reflected by an increased content of smooth muscle and endothelium, NO/cGMP and SOD activity, and reduced cell apoptosis and MDA levels. The effect of Res was improved by adding Tad. In addition, the protein expression of SIRT1 was increased in the Res group, accompanied by decreased p53 and FOXO3a levels. In addition, inhibition of SIRT1 by NAM treatment resulted in adverse results compared with Res treatment. SIRT1 activation ameliorated aging-related erectile dysfunction, supporting the potential of SIRT1 as a target for erectile dysfunction treatment.
Animals
;
Male
;
Rats
;
Cyclic GMP/metabolism*
;
Erectile Dysfunction/metabolism*
;
Nitric Oxide/metabolism*
;
Penile Erection
;
Penis/pathology*
;
Phosphodiesterase 5 Inhibitors/pharmacology*
;
Rats, Sprague-Dawley
;
Sirtuin 1/metabolism*
;
Superoxide Dismutase/metabolism*
;
Tumor Suppressor Protein p53/metabolism*
4.H-NS Represses Biofilm Formation and c-di-GMP Synthesis in Vibrio parahaemolyticus.
Xing Fan XUE ; Miao Miao ZHNAG ; Jun Fang SUN ; Xue LI ; Qi Min WU ; Zhe YIN ; Wen Hui YANG ; Bin NI ; Ling Fei HU ; Dong Sheng ZHOU ; Ren Fei LU ; Yi Quan ZHANG
Biomedical and Environmental Sciences 2022;35(9):821-829
OBJECTIVE:
This study aimed to investigate the regulation of histone-like nucleoid structuring protein (H-NS) on biofilm formation and cyclic diguanylate (c-di-GMP) synthesis in Vibrio parahaemolyticus RIMD2210633.
METHODS:
Regulatory mechanisms were analyzed by the combined utilization of crystal violet staining, quantification of c-di-GMP, quantitative real-time polymerase chain reaction, LacZ fusion, and electrophoretic-mobility shift assay.
RESULTS:
The deletion of hns enhanced the biofilm formation and intracellular c-di-GMP levels in V. parahaemolyticus RIMD2210633. H-NS can bind the upstream promoter-proximal DNA regions of scrA, scrG, VP0117, VPA0198, VPA1176, VP0699, and VP2979 to repress their transcription. These genes encode a group of proteins with GGDEF and/or EAL domains associated with c-di-GMP metabolism.
CONCLUSION
One of the mechanisms by which H-NS represses the biofilm formation by V. parahaemolyticus RIMD2210633 may be via repression of the production of intracellular c-di-GMP.
Bacterial Proteins/metabolism*
;
Biofilms
;
Cyclic GMP/analogs & derivatives*
;
Gene Expression Regulation, Bacterial
;
Gentian Violet
;
Histones/metabolism*
;
Vibrio parahaemolyticus/genetics*
5.Research progress of c-di-GMP in the regulation of Escherichia coli biofilm.
Yunjiang HE ; Weijuan JIA ; Shanshan CHI ; Qinglei MENG ; Yunjiao CHEN ; Xueli WANG
Chinese Journal of Biotechnology 2022;38(8):2811-2820
Escherichia coli biofilm is a complex membrane aggregation produced by the adhesion and secretion of extracellular polymeric substances by E. coli cells aggregated on specific media. Pathogenic E. coli will evade the immune system and the impact of various harmful factors in the environment after the formation of biofilm, causing sustained and even fatal damage to the host. Cyclic diguanosine monophosphate (c-di-GMP) is a second messenger ubiquitous in bacteria and plays a crucial role in regulating biofilm formation. This paper reviewed the recent studies about the role of c-di-GMP in the movement, adhesion, and EPS production mechanism of E. coli during biofilm formation, aiming to provide a basis for inhibiting E. coli biofilm from the perspective of c-di-GMP.
Bacterial Proteins/genetics*
;
Biofilms
;
Cyclic GMP/analogs & derivatives*
;
Escherichia coli/metabolism*
;
Escherichia coli Proteins/metabolism*
;
Gene Expression Regulation, Bacterial
6.Rutaecarpine Inhibits Intimal Hyperplasia in A Balloon-Injured Rat Artery Model.
Yang XU ; Xiu-Ping CHEN ; Feng ZHANG ; Hua-Hua HOU ; Jing-Yi ZHANG ; Shu-Xian LIN ; An-Sheng SUN
Chinese journal of integrative medicine 2018;24(6):429-435
OBJECTIVETo investigate the effect and potential mechanisms of rutaecarpine (Rut) in a rat artery balloon-injury model.
METHODSThe intimal hyperplasia model was established by rubbing the endothelia with a balloon catheter in the common carotid artery (CCA) of rats. Fifty rats were randomly divided into five groups, ie. sham, model, Rut (25, 50 and 75 mg/kg) with 10 rats of each group. The rats were treated with or without Rut (25, 50, 75 mg/kg) by intragastric administration for 14 consecutive days following injury. The morphological changes of the intima were evaluated by hematoxylin-eosin staining. The expressions of proliferating cell nuclear antigen (PCNA) and smooth muscle (SM) α-actin in the ateries were assayed by immunohistochemical staining. The mRNA expressions of c-myc, extracellular signal-regulated kinase 2 (ERK2), MAPK phosphatase-1 (MKP-1) and endothelial nitric oxide synthase (eNOS) were determined by real-time reverse transcription-polymerase chain reaction. The protein expressions of MKP-1 and phosphorylated ERK2 (p-ERK2) were examined by Western blotting. The plasma contents of nitric oxide (NO) and cyclic guanosine 3',5'-monophosphate (cGMP) were also determined.
RESULTSCompared with the model group, Rut treatment significantly decreased intimal thickening and ameliorated endothelial injury (P<0.05 or P<0.01). The positive expression rate of PCNA was decreased, while the expression rate of SM α-actin obviously increased in the vascular wall after Rut (50 and 75 mg/kg) administration (P<0.05 or P<0.01). Furthermore, the mRNA expressions of c-myc, ERK2 and PCNA were downregulated while the expressions of eNOS and MKP-1 were upregulated (P<0.05 or P<0.01). The protein expressions of MKP-1 and the phosphorylation of ERK2 were upregulated and downregulated after Rut (50 and 75 mg/kg) administration (P<0.05 or P<0.01), respectively. In addition, Rut dramatically reversed balloon injury-induced decrease of NO and cGMP in the plasma (P<0.05 or P<0.01).
CONCLUSIONRut could inhibit the balloon injury-induced carotid intimal hyperplasia in rats, possibly mediated by promotion of NO production and inhibiting ERK2 signal transduction pathways.
Actins ; metabolism ; Animals ; Carotid Arteries ; drug effects ; metabolism ; pathology ; Carotid Artery Injuries ; drug therapy ; genetics ; pathology ; Cyclic GMP ; blood ; Disease Models, Animal ; Gene Expression Regulation ; drug effects ; Hyperplasia ; Indole Alkaloids ; pharmacology ; therapeutic use ; Male ; Nitric Oxide ; blood ; Phosphorylation ; drug effects ; Proliferating Cell Nuclear Antigen ; metabolism ; Quinazolines ; pharmacology ; therapeutic use ; RNA, Messenger ; genetics ; metabolism ; Rats, Sprague-Dawley ; Tunica Intima ; drug effects ; pathology
7.Beneficial Effect of Berberis amurensis Rupr. on Penile Erection.
Rui TAN ; Yun Jung LEE ; Kyung Woo CHO ; Dae Gill KANG ; Ho Sub LEE
Chinese journal of integrative medicine 2018;24(6):448-454
OBJECTIVETo investigate whether the methanol extract of Berberis amurensis Rupr. (BAR) augments penile erection using in vitro and in vivo experiments.
METHODSThe ex vivo study used corpus cavernosum strips prepared from adult male New Zealand White rabbits. In in vivo studies for intracavernous pressure (ICP), blood pressure, mean arterial pressure (MAP), and increase of peak ICP were continuously monitored during electrical stimulation of Sprague-Dawley rats.
RESULTSPreconstricted with phenylephrine (PE) in isolated endotheliumintact rabbit corus cavernosum, BAR relaxed penile smooth muscle in a dose-dependent manner, which was inhibited by pretreatment with NG-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, and H-[1,2,4]-oxadiazole-[4,3-α]-quinoxalin-1-one, a soluble guanylyl cclase inhibitor. BAR significantly relaxed penile smooth muscles dose-dependently in ex vivo, and this was inhibited by pretreatment with L-NAME H-[1,2,4]-oxadiazole-[4,3-α]-quinoxalin-1-one. BAR-induced relaxation was significantly attenuated by pretreatment with tetraethylammonium (TEA, P<0.01), a nonselective K channel blocker, 4-aminopyridine (4-AP, P<0.01), a voltage-dependent K channel blocker, and charybdotoxin (P<0.01), a large and intermediate conductance Ca sensitive-K channel blocker, respectively. BAR induced an increase in peak ICP, ICP/MAP ratio and area under the curve dose dependently.
CONCLUSIONBAR augments penile erection via the nitric oxide/cyclic guanosine monophosphate system and Ca sensitive-K (BK and IK) channels in the corpus cavernosum.
Animals ; Area Under Curve ; Berberis ; chemistry ; Blood Pressure ; drug effects ; Cyclic GMP ; metabolism ; Epoprostenol ; pharmacology ; In Vitro Techniques ; Indomethacin ; pharmacology ; Male ; Models, Biological ; Muscle Relaxation ; drug effects ; Muscle, Smooth ; drug effects ; physiology ; NG-Nitroarginine Methyl Ester ; pharmacology ; Nitric Oxide ; metabolism ; Penile Erection ; drug effects ; Phenylephrine ; pharmacology ; Plant Extracts ; pharmacology ; Potassium Channel Blockers ; pharmacology ; Potassium Channels ; metabolism ; Pressure ; Rabbits
8.Calpain inhibition improves erectile function in diabetic mice via upregulating endothelial nitric oxide synthase expression and reducing apoptosis.
Hao LI ; Li-Ping CHEN ; Tao WANG ; Shao-Gang WANG ; Ji-Hong LIU
Asian Journal of Andrology 2018;20(4):342-348
Calpain activation contributes to hyperglycemia-induced endothelial dysfunction and apoptosis. This study was designed to investigate the role of calpain inhibition in improving diabetic erectile dysfunction (ED) in mice. Thirty-eight-week-old male C57BL/6J mice were divided into three groups: (1) nondiabetic control group, (2) diabetic mice + vehicle group, and (3) diabetic mice + MDL28170 (an inhibitor of calpain) group. Type 1 diabetes was induced by intraperitoneal injection of streptozotocin at 60 mg kg-1 body weight for 5 consecutive days. Thirteen weeks later, diabetic mice were treated with MDL28170 or vehicle for 4 weeks. The erectile function was assessed by electrical stimulation of the cavernous nerve. Penile tissues were collected for measurement of calpain activity and the endothelial nitric oxide synthase (eNOS)-nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) pathway. Terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate nick end labeling (TUNEL) staining was used to evaluate apoptosis. Caspase-3 expression and activity were also measured to determine apoptosis. Our results showed that erectile function was enhanced by MDL28170 treatment in diabetic mice compared with the vehicle diabetic group. No differences in calpain-1 and calpain-2 expressions were observed among the three groups. However, calpain activity was increased in the diabetic group and reduced by MDL28170. The eNOS-NO-cGMP pathway was upregulated by MDL28170 treatment in diabetic mice. Additionally, MDL28170 could attenuate apoptosis and increase the endothelium and smooth muscle levels in corpus cavernosum. Inhibition of calpain could improve erectile function, probably by upregulating the eNOS-NO-cGMP pathway and reducing apoptosis.
Animals
;
Apoptosis/drug effects*
;
Calpain/antagonists & inhibitors*
;
Cyclic GMP/biosynthesis*
;
Diabetes Complications/drug therapy*
;
Diabetes Mellitus, Experimental/complications*
;
Dipeptides/therapeutic use*
;
Endothelium/metabolism*
;
Enzyme Inhibitors/therapeutic use*
;
Erectile Dysfunction/etiology*
;
In Situ Nick-End Labeling
;
Male
;
Mice
;
Mice, Inbred C57BL
;
Muscle, Smooth/metabolism*
;
Nitric Oxide Synthase Type III/biosynthesis*
;
Penis/enzymology*
;
Up-Regulation
9.Pancreatic kininogenase improves erectile function in streptozotocin-induced type 2 diabetic rats with erectile dysfunction.
Guo-Tao CHEN ; Bai-Bing YANG ; Jian-Huai CHEN ; Zheng ZHANG ; Lei-Lei ZHU ; He-Song JIANG ; Wen YU ; Yun CHEN ; Yu-Tian DAI
Asian Journal of Andrology 2018;20(5):448-453
Erectile dysfunction (ED) associated with type 2 diabetes is a severe problem that requires effective treatment. Pancreatic kininogenase (PK) has the potential to improve the erectile function of ED patients. This study aims to investigate the effect of PK on erectile function in streptozotocin-induced type 2 diabetic ED rats. To achieve this goal, we divided male Sprague-Dawley rats into five groups. One group was not treated, and the other four groups were treated with saline, sildenafil, PK or sildenafil, and PK, respectively, for 4 weeks after the induction of type 2 diabetic ED. Then, intracavernous pressure under cavernous nerve stimulation was measured, and penile tissue was collected for further study. Endothelial nitric oxide synthase levels, smooth muscle content, endothelium content, cyclic guanosine monophosphate (cGMP) levels in the corpus cavernosum, and neuronal nitric oxide synthase levels in the dorsal penile nerve were measured. Improved erectile function and endothelium and smooth muscle content in the corpus cavernosum were observed in diabetic ED rats. When treating diabetic ED rats with PK and sildenafil at the same time, a better therapeutic effect was achieved. These data demonstrate that intraperitoneal injection of PK can improve erectile function in a rat model of type 2 diabetic ED. With further research on specific mechanisms of erectile function improvement, PK may become a novel treatment for diabetic ED.
Animals
;
Cyclic GMP/metabolism*
;
Diabetes Mellitus, Experimental/physiopathology*
;
Erectile Dysfunction/physiopathology*
;
Kallikreins/therapeutic use*
;
Male
;
Muscle, Smooth, Vascular/physiopathology*
;
Nitric Oxide Synthase Type I/metabolism*
;
Nitric Oxide Synthase Type III/metabolism*
;
Penile Erection/physiology*
;
Penis/metabolism*
;
Rats
;
Rats, Sprague-Dawley
;
Sildenafil Citrate/therapeutic use*
;
Treatment Outcome
;
Urological Agents/therapeutic use*
10.Structural insights into the regulatory mechanism of the Pseudomonas aeruginosa YfiBNR system.
Min XU ; Xuan YANG ; Xiu-An YANG ; Lei ZHOU ; Tie-Zheng LIU ; Zusen FAN ; Tao JIANG
Protein & Cell 2016;7(6):403-416
YfiBNR is a recently identified bis-(3'-5')-cyclic dimeric GMP (c-di-GMP) signaling system in opportunistic pathogens. It is a key regulator of biofilm formation, which is correlated with prolonged persistence of infection and antibiotic drug resistance. In response to cell stress, YfiB in the outer membrane can sequester the periplasmic protein YfiR, releasing its inhibition of YfiN on the inner membrane and thus provoking the diguanylate cyclase activity of YfiN to induce c-di-GMP production. However, the detailed regulatory mechanism remains elusive. Here, we report the crystal structures of YfiB alone and of an active mutant YfiB(L43P) complexed with YfiR with 2:2 stoichiometry. Structural analyses revealed that in contrast to the compact conformation of the dimeric YfiB alone, YfiB(L43P) adopts a stretched conformation allowing activated YfiB to penetrate the peptidoglycan (PG) layer and access YfiR. YfiB(L43P) shows a more compact PG-binding pocket and much higher PG binding affinity than wild-type YfiB, suggesting a tight correlation between PG binding and YfiB activation. In addition, our crystallographic analyses revealed that YfiR binds Vitamin B6 (VB6) or L-Trp at a YfiB-binding site and that both VB6 and L-Trp are able to reduce YfiB(L43P)-induced biofilm formation. Based on the structural and biochemical data, we propose an updated regulatory model of the YfiBNR system.
Amino Acid Sequence
;
Bacterial Proteins
;
chemistry
;
genetics
;
metabolism
;
Binding Sites
;
Biofilms
;
Crystallography, X-Ray
;
Cyclic GMP
;
analogs & derivatives
;
metabolism
;
Dimerization
;
Molecular Dynamics Simulation
;
Molecular Sequence Data
;
Mutagenesis
;
Protein Structure, Quaternary
;
Pseudomonas aeruginosa
;
metabolism
;
Sequence Alignment
;
Tryptophan
;
chemistry
;
metabolism
;
Vitamin B 6
;
chemistry
;
metabolism

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