Natural genetic diversity in the potato resistance gene RB confers suppression avoidance from Phytophthora effector IPI-O4

RB is a potato gene that provides resistance to a broad spectrum of genotypes of the late blight pathogen Phytophthora infestans. RB belongs to the CC-NB-LRR (coiled-coil, nucleotide-binding, leucine-rich repeat) class of resistance (R) genes, a major component of the plant immune system. The RB protein detects the presence of Class I and II IPI-O effectors from P. infestans to initiate a hypersensitive resistance response, but this activity is suppressed in the presence of the Class III effector IPI-O4. Using natural genetic variation of RB within potato wild relatives, we identified two amino acids in the CC domain that alter interactions needed for suppression of resistance by IPI-O4. We have found that separate modification of these amino acids in RB can diminish or expand the resistance capability of this protein against P. infestans in both Nicotiana benthamiana and potato. Our results demonstrate that increased knowledge of the molecular mechanisms that determine resistance activation and R protein suppression by effectors can be utilized to tailor-engineer genes with the potential to provide increased durability.

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Natural genetic diversity in the potato resistance gene RB confers suppression avoidance from Phytophthora effector IPI-O4

10.1101/2020.11.13.381905 ◽

2020 ◽

Author(s):

Hari S. Karki ◽

Sidrat Abdullah ◽

Yu Chen ◽

Dennis A. Halterman

Keyword(s):

Amino Acids ◽

Molecular Mechanisms ◽

Coiled Coil ◽

Class Iii ◽

Hypersensitive Resistance ◽

Resistance Response ◽

Natural Genetic Variation ◽

Repeat Class ◽

Potato Resistance ◽

Late Blight Pathogen

ABSTRACTRB is a potato gene that provides resistance to a broad spectrum of genotypes of the late blight pathogen Phytophthora infestans. RB belongs to the CC-NB-LRR (coiled-coil, nucleotide-binding, leucine-rich repeat) class of resistance (R) genes, a major component of the plant immune system. It directly interacts with Class I and II IPI-O effectors from P. infestans to initiate a hypersensitive resistance response, but this activity is suppressed in the presence of the Class III effector IPI-O4. Using natural genetic variation of RB within potato wild relatives, we identified two amino acids in the CC domain that alter interactions needed for suppression of resistance by IPI-O4. We have found that separate modification of these amino acids in RB can diminish or enhance the resistance capability of this protein against P. infestans in both Nicotiana benthamiana and potato. Our results demonstrate that increased knowledge of the molecular mechanisms that determine resistance activation and R protein suppression by effectors can be utilized to tailor-engineer genes with the potential to provide increased durability.

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Pseudomonas syringae Effector AvrPphB Suppresses AvrB-Induced Activation of RPM1 but Not AvrRpm1-Induced Activation

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-08-14-0248-r ◽

2015 ◽

Vol 28 (6) ◽

pp. 727-735 ◽

Cited By ~ 24

Author(s):

Andrew R. Russell ◽

Tom Ashfield ◽

Roger W. Innes

Keyword(s):

Disease Resistance ◽

Protein Kinase ◽

Molecular Mechanism ◽

Pseudomonas Syringae ◽

Hypersensitive Response ◽

Hypersensitive Resistance ◽

Nicotiana Glutinosa ◽

Resistance Response ◽

Interacting Protein ◽

Soybean Plants

The Pseudomonas syringae effector AvrB triggers a hypersensitive resistance response in Arabidopsis and soybean plants expressing the disease resistance (R) proteins RPM1 and Rpg1b, respectively. In Arabidopsis, AvrB induces RPM1-interacting protein kinase (RIPK) to phosphorylate a disease regulator known as RIN4, which subsequently activates RPM1-mediated defenses. Here, we show that AvrPphB can suppress activation of RPM1 by AvrB and this suppression is correlated with the cleavage of RIPK by AvrPphB. Significantly, AvrPphB does not suppress activation of RPM1 by AvrRpm1, suggesting that RIPK is not required for AvrRpm1-induced modification of RIN4. This observation indicates that AvrB and AvrRpm1 recognition is mediated by different mechanisms in Arabidopsis, despite their recognition being determined by a single R protein. Moreover, AvrB recognition but not AvrRpm1 recognition is suppressed by AvrPphB in soybean, suggesting that AvrB recognition requires a similar molecular mechanism in soybean and Arabidopsis. In support of this, we found that phosphodeficient mutations in the soybean GmRIN4a and GmRIN4b proteins are sufficient to block Rpg1b-mediated hypersensitive response in transient assays in Nicotiana glutinosa. Taken together, our results indicate that AvrB and AvrPphB target a conserved defense signaling pathway in Arabidopsis and soybean that includes RIPK and RIN4.

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Molecular Characterization of the Von Willebrand Factor Type D Domain of Vitellogenin from Takifugu flavidus

Marine Drugs ◽

10.3390/md19040181 ◽

2021 ◽

Vol 19 (4) ◽

pp. 181

Author(s):

Kun Qiao ◽

Caiyun Jiang ◽

Min Xu ◽

Bei Chen ◽

Wenhui Qiu ◽

...

Keyword(s):

Amino Acids ◽

Von Willebrand Factor ◽

Molecular Mechanisms ◽

Protein Domain ◽

Type D ◽

Protein Toxin ◽

Factor Type ◽

Von Willebrand ◽

Willebrand Factor

The von Willebrand factor type D (VWD) domain in vitellogenin has recently been found to bind tetrodotoxin. The way in which this protein domain associates with tetrodotoxin and participates in transporting tetrodotoxin in vivo remains unclear. A cDNA fragment of the vitellogenin gene containing the VWD domain from pufferfish (Takifugu flavidus) (TfVWD) was cloned. Using in silico structural and docking analyses of the predicted protein, we determined that key amino acids (namely, Val115, ASP116, Val117, and Lys122) in TfVWD mediate its binding to tetrodotoxin, which was supported by in vitro surface plasmon resonance analysis. Moreover, incubating recombinant rTfVWD together with tetrodotoxin attenuated its toxicity in vivo, further supporting protein–toxin binding and indicating associated toxicity-neutralizing effects. Finally, the expression profiling of TfVWD across different tissues and developmental stages indicated that its distribution patterns mirrored those of tetrodotoxin, suggesting that TfVWD may be involved in tetrodotoxin transport in pufferfish. For the first time, this study reveals the amino acids that mediate the binding of TfVWD to tetrodotoxin and provides a basis for further exploration of the molecular mechanisms underlying the enrichment and transfer of tetrodotoxin in pufferfish.

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Congenital adrenal hyperplasia: molecular mechanisms resulting in 21-hydroxylase deficiency

Acta Endocrinologica ◽

10.1530/acta.0.112s315 ◽

1986 ◽

Vol 113 (4_Suppl) ◽

pp. S315-S320 ◽

Cited By ~ 7

Author(s):

Patricia A. Donohoue ◽

Cornelis Van Dop ◽

Nicholas Jospe ◽

Claude J. Migeon

Keyword(s):

Congenital Adrenal Hyperplasia ◽

Molecular Mechanisms ◽

Sequence Data ◽

Phenotypic Expression ◽

Restriction Pattern ◽

Class Iii ◽

Adrenal Hyperplasia ◽

Hydroxylase Deficiency ◽

Wide Range ◽

21 Hydroxylase Deficiency

Abstract 21-Hydroxylase deficiency resulting in congenital adrenal hyperplasia (CAH) is a HLA-linked autosomal recessive disorder that has a wide range of phenotypic expression. Two homologous 21-hydroxylase genes (21-OHA and 21-OHB) occur within the Class III region of the major histocompatibility complex, but only one (21-OHB) appears to function in adrenal steroidogenesis. Our restriction maps, and initial sequence data from White et al. (Pediatr Res 20:274A (1986)) for the two human 21-OH genes reveal a high degree of homology between these genes and a reading frame shift mutation in the 21-OHA gene respectively. Among fourteen control subjects, the intragenic restriction patterns of the 21-OHA and 21-OHB genes are invariant. The few restriction fragment length polymorphisms (RFLPs) found in some controls result from polymorphic restriction sites outside the 21-OH genes. In patients with CAH, several different mechanisms for mutation of the 21-OHB gene have been described: 1) deletion of the unique sequences of the 21-OHB gene, 2) conversion of the unique sequences of the 21-OHB gene to those of 21-OHA, and 3) mutations of 21-OHB which do not result in a detectable alteration of restriction pattern (e.g., point mutations). Duplication of the 21-OHA gene has been found in some patients with attenuated CAH; however, the significance of this finding remains unclear.

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quick-to-court, a Drosophila Mutant With Elevated Levels of Sexual Behavior, Is Defective in a Predicted Coiled-Coil Protein

Genetics ◽

10.1093/genetics/154.4.1627 ◽

2000 ◽

Vol 154 (4) ◽

pp. 1627-1637

Author(s):

Peter Gaines ◽

Laurie Tompkins ◽

Craig T Woodard ◽

John R Carlson

Keyword(s):

Sexual Behavior ◽

Molecular Mechanisms ◽

Reproductive Tract ◽

Coiled Coil ◽

Virgin Female ◽

Male Courtship ◽

Male Reproductive Tract ◽

New Gene ◽

Olfactory Organs ◽

Drosophila Mutant

Abstract Remarkably little is known about the molecular mechanisms that drive sexual behavior. We have identified a new gene, quick-to-court (qtc), whose mutations cause males to show high levels of male-male courtship. qtc males also show a novel phenotype: when placed in the presence of a virgin female, they begin courtship abnormally quickly. qtc mutations are striking in their specificity, in that many aspects of male sexual behavior are normal. We have cloned the qtc gene and found that it encodes a predicted coiled-coil protein and is expressed in the olfactory organs, central nervous system, and male reproductive tract.

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Receptor and Molecular Mechanism of AGGF1 Signaling in Endothelial Cell Functions and Angiogenesis

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvbaha.121.316867 ◽

2021 ◽

Author(s):

Jingjing Wang ◽

Huixin Peng ◽

Ayse Anil Timur ◽

Vinay Pasupuleti ◽

Yufeng Yao ◽

...

Keyword(s):

Amino Acids ◽

Endothelial Cell ◽

Neutralizing Antibodies ◽

Molecular Mechanisms ◽

Capillary Tube ◽

Therapeutic Angiogenesis ◽

Angiogenic Factor ◽

Single Amino Acid ◽

Binding Motif ◽

Cell Functions

Objective: Angiogenic factor AGGF1 (angiogenic factor and G-patch and FHA [Forkhead-associated] domain 1) promotes angiogenesis as potently as VEGFA (vascular endothelial growth factor A) and regulates endothelial cell (EC) proliferation, migration, specification of multipotent hemangioblasts and venous ECs, hematopoiesis, and vascular development and causes vascular disease Klippel-Trenaunay syndrome when mutated. However, the receptor for AGGF1 and the underlying molecular mechanisms remain to be defined. Approach and Results: Using functional blocking studies with neutralizing antibodies, we identified α5β1 as the receptor for AGGF1 on ECs. AGGF1 interacts with α5β1 and activates FAK (focal adhesion kinase), Src, and AKT. Functional analysis of 12 serial N-terminal deletions and 13 C-terminal deletions by every 50 amino acids mapped the angiogenic domain of AGGF1 to a domain between amino acids 604-613 (FQRDDAPAS). The angiogenic domain is required for EC adhesion and migration, capillary tube formation, and AKT activation. The deletion of the angiogenic domain eliminated the effects of AGGF1 on therapeutic angiogenesis and increased blood flow in a mouse model for peripheral artery disease. A 40-mer or 15-mer peptide containing the angiogenic domain blocks AGGF1 function, however, a 15-mer peptide containing a single amino acid mutation from −RDD- to −RGD- (a classical RGD integrin-binding motif) failed to block AGGF1 function. Conclusions: We have identified integrin α5β1 as an EC receptor for AGGF1 and a novel AGGF1-mediated signaling pathway of α5β1-FAK-Src-AKT for angiogenesis. Our results identify an FQRDDAPAS angiogenic domain of AGGF1 crucial for its interaction with α5β1 and signaling.

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Abstract 3380: Acetylation-dependent Regulation Of Notch1 Signaling In Endothelial Cells

Circulation ◽

10.1161/circ.118.suppl_18.s_415-c ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Virginia Guarani ◽

Franck Dequiedt ◽

Andreas M Zeiher ◽

Stefanie Dimmeler ◽

Michael Potente

Keyword(s):

Endothelial Cells ◽

Notch Signaling ◽

Cell Fate ◽

Molecular Mechanisms ◽

Trichostatin A ◽

Notch Pathway ◽

Dependent Manner ◽

Class Iii ◽

Cell Fate Decisions ◽

Knock Down

The Notch signaling pathway is a versatile regulator of cell fate decisions and plays an essential role for embryonic and postnatal vascular development. As only modest differences in Notch pathway activity suffice to determine dramatic differences in blood vessel development, this pathway is tightly regulated by a variety of molecular mechanisms. Reversible acetylation has emerged as an important post-translational modification of several non-histone proteins, which are targeted by histone deacetylases (HDACs). Here, we report that specifically the Notch1 intracellular domain (NICD) is itself an acetylated protein and that its acetylation level is tightly regulated by the SIRT1 deacetylase, which we have previously identified as a key regulator of endothelial angiogenic functions during vascular growth. Coexpression of NICD with histone acetyltransferases such as p300 or PCAF induced a dose- and time-dependent acetylation of NICD. Blocking HDAC activity using the class III HDAC inhibitor nicotinamid (NAM), but not the class I/II HDAC inhibior trichostatin A, resulted in a significant increase of NICD acetylation suggesting that NICD is targetd by class III HDACs for deacetylation. Among the class III HDACs with deacetylase activity (SIRT1, 2, 3, 5), knock down of specifically SIRT1 resulted in enhanced acetylation of NICD. Moreover, wild type SIRT1, but not a catalytically inactive mutant catalyzed the deacetylation of NICD in a nicotinamid-dependent manner. SIRT1, but SIRT2, SIRT3 or SIRT5, associated with NICD through its catalytic domain demonstrating that SIRT1 is a direct NICD deacetylase. Enhancing NICD acetylation by either overexpression of p300 or inhibition of SIRT1 activity using NAM or RNAi-mediated knock down resulted in enhanced NICD protein stability by blocking its ubiquitin-mediated degradation. Consistent with these results, loss of SIRT1 amplified Notch target gene expression in endothelial cells in response to NICD overexpression or treatment with the Notch ligand Dll4. In summary, our results identify reversible acetylation of NICD as a novel molecular mechanism to control Notch signaling and suggest that deacetylation of NICD by SIRT1 plays a key role in the dynamic regulation of Notch signaling in endothelial cells.

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LATERAL FLORET 1 induced the three-florets spikelet in rice

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1700504114 ◽

2017 ◽

Vol 114 (37) ◽

pp. 9984-9989 ◽

Cited By ~ 24

Author(s):

Ting Zhang ◽

Yunfeng Li ◽

Ling Ma ◽

Xianchun Sang ◽

Yinghua Ling ◽

...

Keyword(s):

Leucine Zipper ◽

Molecular Mechanisms ◽

Ectopic Expression ◽

Target Sequence ◽

Class Iii ◽

Rice Mutant ◽

Inflorescence Structure ◽

Meristem Maintenance ◽

Floral Meristems ◽

Sterile Lemma

The spikelet is a unique inflorescence structure in grass. The molecular mechanisms behind the development and evolution of the spikelet are far from clear. In this study, a dominant rice mutant, lateral florets 1 (lf1), was characterized. In the lf1 spikelet, lateral floral meristems were promoted unexpectedly and could generally blossom into relatively normal florets. LF1 encoded a class III homeodomain-leucine zipper (HD-ZIP III) protein, and the site of mutation in lf1 was located in a putative miRNA165/166 target sequence. Ectopic expression of both LF1 and the meristem maintenance gene OSH1 was detected in the axil of the sterile lemma primordia of the lf1 spikelet. Furthermore, the promoter of OSH1 could be bound directly by LF1 protein. Collectively, these results indicate that the mutation of LF1 induces ectopic expression of OSH1, which results in the initiation of lateral meristems to generate lateral florets in the axil of the sterile lemma. This study thus offers strong evidence in support of the “three-florets spikelet” hypothesis in rice.

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Molecular Evolution of Tubulins in Diatoms

International Journal of Molecular Sciences ◽

10.3390/ijms23020618 ◽

2022 ◽

Vol 23 (2) ◽

pp. 618

Author(s):

Kirill V. Khabudaev ◽

Darya P. Petrova ◽

Yekaterina D. Bedoshvili ◽

Yelena V. Likhoshway ◽

Mikhail A. Grachev

Keyword(s):

Amino Acids ◽

Posttranslational Modification ◽

Molecular Mechanisms ◽

Morphological Diversity ◽

Amino Acid Sequences ◽

Transcriptome Data ◽

Eukaryotic Proteins ◽

Large Diatom ◽

Species Specific ◽

Β Tubulin

Microtubules are formed by α- and β-tubulin heterodimers nucleated with γ-tubulin. Tubulins are conserved eukaryotic proteins. Previously, it was shown that microtubules are involved in diatom silica frustule morphogenesis. Diatom frustules are varied, and their morphology is species-specific. Despite the attractiveness of the problem of elucidating the molecular mechanisms of genetically programmed morphogenesis, the structure and evolution of diatom tubulins have not been studied previously. Based on available genomic and transcriptome data, we analyzed the phylogeny of the predicted amino acid sequences of diatom α-, β- and γ-tubulins and identified five groups for α-tubulins, six for β-tubulins and four for γ-tubulins. We identified characteristic amino acids of each of these groups and also analyzed possible posttranslational modification sites of diatom tubulins. According to our results, we assumed what changes occurred in the diatom tubulin structures during their evolution. We also identified which tubulin groups are inherent in large diatom taxa. The similarity between the evolution of diatom tubulins and the evolution of diatoms suggests that molecular changes in α-, β- and γ-tubulins could be one of the factors in the formation of a high morphological diversity of diatoms.

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Dietary essential amino acids restore liver metabolism in ovariectomized mice via hepatic estrogen receptor α

Nature Communications ◽

10.1038/s41467-021-27272-x ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Sara Della Torre ◽

Valeria Benedusi ◽

Giovanna Pepe ◽

Clara Meda ◽

Nicoletta Rizzi ◽

...

Keyword(s):

Amino Acids ◽

Estrogen Receptor ◽

Weight Gain ◽

Molecular Mechanisms ◽

Liver Lipid ◽

Essential Amino Acids ◽

Estrogen Receptor Α ◽

Metabolic Effects ◽

Ovariectomized Mice ◽

Dietary Treatments

AbstractIn female mammals, the cessation of ovarian functions is associated with significant metabolic alterations, weight gain, and increased susceptibility to a number of pathologies associated with ageing. The molecular mechanisms triggering these systemic events are unknown because most tissues are responsive to lowered circulating sex steroids. As it has been demonstrated that isoform alpha of the estrogen receptor (ERα) may be activated by both estrogens and amino acids, we test the metabolic effects of a diet enriched in specific amino acids in ovariectomized (OVX) mice. This diet is able to block the OVX-induced weight gain and fat deposition in the liver. The use of liver-specific ERα KO mice demonstrates that the hepatic ERα, through the control of liver lipid metabolism, has a key role in the systemic response to OVX. The study suggests that the liver ERα might be a valuable target for dietary treatments for the post-menopause.

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