Induction of Stomatal Closure by Vanadate or a Light/Dark Transition Involves Ca2+-Calmodulin-Dependent Protein Phosphorylations

AbstractPattern-triggered immunity and effector-triggered immunity are two primary forms of innate immunity in land plants. The molecular components and connecting nodes of pattern-triggered immunity and effector-triggered immunity are not fully understood. Here, we report that the Arabidopsis calcium-dependent protein kinase CPK3 is a key regulator of both pattern-triggered immunity and effector-triggered immunity. In vitro and in vivo phosphorylation assays, coupled with genetic and cell biology-based analyses, show that actin-depolymerization factor 4 (ADF4) is a physiological substrate of CPK3, and that phosphorylation of ADF4 by CPK3 governs actin cytoskeletal organization associated with pattern-triggered immunity. CPK3 regulates stomatal closure induced by flg22 and is required for resistance to Pst DC3000. Our data further demonstrates that CPK3 is required for resistance to Pst DC3000 carrying the effector AvrPphB. These results suggest that CPK3 is a missing link between cytoskeleton organization, pattern-triggered immunity and effector-triggered immunity.

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The Calcium-Dependent Protein Kinase CPK33 Mediates Strigolactone-Induced Stomatal Closure in Arabidopsis thaliana

Frontiers in Plant Science ◽

10.3389/fpls.2019.01630 ◽

2019 ◽

Vol 10 ◽

Author(s):

Xuening Wang ◽

Shuo Lv ◽

Xiangyu Han ◽

Xiongjuan Guan ◽

Xiong Shi ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Protein Kinase ◽

Stomatal Closure ◽

Dependent Protein Kinase ◽

Calcium Dependent ◽

Dependent Protein ◽

Calcium Dependent Protein Kinase

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Arabidopsis KASH Proteins SINE1 and SINE2 Are Involved in Microtubule Reorganization During ABA-Induced Stomatal Closure

Frontiers in Plant Science ◽

10.3389/fpls.2020.575573 ◽

2020 ◽

Vol 11 ◽

Author(s):

Alecia Biel ◽

Morgan Moser ◽

Iris Meier

Keyword(s):

Stomatal Closure ◽

Oxygen Species ◽

Actin Organization ◽

Calcium Dependent ◽

Signaling Mechanisms ◽

Dependent Protein ◽

Calcium Dependent Protein Kinases ◽

Complex Signaling ◽

Precise Role

Abscisic acid (ABA) induces stomatal closure by utilizing complex signaling mechanisms, allowing for sessile plants to respond rapidly to ever-changing environmental conditions. ABA regulates the activity of plasma membrane ion channels and calcium-dependent protein kinases, Ca2+ oscillations, and reactive oxygen species (ROS) concentrations. Throughout ABA-induced stomatal closure, the cytoskeleton undergoes dramatic changes that appear important for efficient closure. However, the precise role of this cytoskeletal reorganization in stomatal closure and the nature of its regulation are unknown. We have recently shown that the plant KASH proteins SINE1 and SINE2 are connected to actin organization during ABA-induced stomatal closure but their role in microtubule (MT) organization remains to be investigated. We show here that depolymerizing MTs using oryzalin can restore ABA-induced stomatal closure deficits in sine1-1 and sine2-1 mutants. GFP-MAP4-visualized MT organization is compromised in sine1-1 and sine2-1 mutants during ABA-induced stomatal closure. Loss of SINE1 or SINE2 results in loss of radially organized MT patterning in open guard cells, aberrant MT organization during stomatal closure, and an overall decrease in the number of MT filaments or bundles. Thus, SINE1 and SINE2 are necessary for establishing MT patterning and mediating changes in MT rearrangement, which is required for ABA-induced stomatal closure.

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Calcium-Dependent Protein Kinase CPK6 Positively Functions in Induction by Yeast Elicitor of Stomatal Closure and Inhibition by Yeast Elicitor of Light-Induced Stomatal Opening in Arabidopsis

PLANT PHYSIOLOGY ◽

10.1104/pp.113.224055 ◽

2013 ◽

Vol 163 (2) ◽

pp. 591-599 ◽

Cited By ~ 41

Author(s):

W. Ye ◽

D. Muroyama ◽

S. Munemasa ◽

Y. Nakamura ◽

I. C. Mori ◽

...

Keyword(s):

Protein Kinase ◽

Stomatal Closure ◽

Stomatal Opening ◽

Dependent Protein Kinase ◽

Yeast Elicitor ◽

Calcium Dependent ◽

Dependent Protein ◽

Calcium Dependent Protein Kinase

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THI1, a Thiamine Thiazole Synthase, Interacts with Ca2+-Dependent Protein Kinase CPK33 and Modulates the S-Type Anion Channels and Stomatal Closure in Arabidopsis

PLANT PHYSIOLOGY ◽

10.1104/pp.15.01649 ◽

2015 ◽

Vol 170 (2) ◽

pp. 1090-1104 ◽

Cited By ~ 26

Author(s):

Chun-Long Li ◽

Mei Wang ◽

Xiao-Meng Wu ◽

Dong-Hua Chen ◽

Hong-Jun Lv ◽

...

Keyword(s):

Protein Kinase ◽

Stomatal Closure ◽

Anion Channels ◽

Dependent Protein Kinase ◽

Dependent Protein

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Calcium specificity signaling mechanisms in abscisic acid signal transduction in Arabidopsis guard cells

eLife ◽

10.7554/elife.03599 ◽

2015 ◽

Vol 4 ◽

Cited By ~ 60

Author(s):

Benjamin Brandt ◽

Shintaro Munemasa ◽

Cun Wang ◽

Desiree Nguyen ◽

Taiming Yong ◽

...

Keyword(s):

Signal Transduction ◽

Abscisic Acid ◽

Stomatal Closure ◽

Guard Cells ◽

In Planta ◽

Signaling Specificity ◽

Downstream Signaling ◽

Calcium Dependent ◽

Quadruple Mutant ◽

Dependent Protein

A central question is how specificity in cellular responses to the eukaryotic second messenger Ca2+ is achieved. Plant guard cells, that form stomatal pores for gas exchange, provide a powerful system for in depth investigation of Ca2+-signaling specificity in plants. In intact guard cells, abscisic acid (ABA) enhances (primes) the Ca2+-sensitivity of downstream signaling events that result in activation of S-type anion channels during stomatal closure, providing a specificity mechanism in Ca2+-signaling. However, the underlying genetic and biochemical mechanisms remain unknown. Here we show impairment of ABA signal transduction in stomata of calcium-dependent protein kinase quadruple mutant plants. Interestingly, protein phosphatase 2Cs prevent non-specific Ca2+-signaling. Moreover, we demonstrate an unexpected interdependence of the Ca2+-dependent and Ca2+-independent ABA-signaling branches and the in planta requirement of simultaneous phosphorylation at two key phosphorylation sites in SLAC1. We identify novel mechanisms ensuring specificity and robustness within stomatal Ca2+-signaling on a cellular, genetic, and biochemical level.

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Subtle Impact of Akt1 and Akt3 on Exploratory Behavior in Gene Targeted Mice

Zeitschrift für Psychologie ◽

10.1027/2151-2604/a000218 ◽

2015 ◽

Vol 223 (3) ◽

pp. 173-180 ◽

Cited By ~ 1

Author(s):

Christina Leibrock ◽

Michael Hierlmeier ◽

Undine E. Lang ◽

Florian Lang

Keyword(s):

Forced Swimming Test ◽

Open Field Test ◽

Wild Type ◽

Average Speed ◽

Closed Area ◽

Light Area ◽

Swimming Test ◽

The Impact ◽

Center Area ◽

Dark Transition

Abstract. The present study explored the impact of Akt1 and Akt3 on behavior. Akt1 (akt1-/-) and Akt3 (akt3-/-) knockout mice were compared to wild type (wt) mice. The akt1-/- mice, akt3-/- mice, and wt mice were similar in most parameters of the open-field test. However, the distance traveled in the center area was slightly but significantly less in akt3-/- mice than in wt mice. In the light/dark transition test akt1-/- mice had significantly lower values than wt mice and akt3-/- mice for distance traveled, number of rearings, rearing time in the light area, as well as time spent and distance traveled in the entrance area. They were significantly different from akt3-/- mice in the distance traveled, visits, number of rearings, rearing time in the light area, as well as time spent, distance traveled, number of rearings, and rearing time in the entrance area. In the O-maze the time spent, and the visits to open arms, as well as the number of protected and unprotected headdips were significantly less in akt1-/- mice than in wt mice, whereas the time spent in closed arms was significantly more in akt1-/- mice than in wt mice. Protected and unprotected headdips were significantly less in akt3-/- mice than in wt mice. In closed area, akt3-/- mice traveled a significantly larger distance at larger average speed than akt1-/- mice. No differences were observed between akt1-/- mice, akt3-/- mice and wt-type mice in the time of floating during the forced swimming test. In conclusion, akt1-/- mice and less so akt3-/ mice display subtle changes in behavior.

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Protein S and C4b-Binding Protein: Components Involved in the Regulation of the Protein C Anticoagulant System

Thrombosis and Haemostasis ◽

10.1055/s-0038-1646373 ◽

1991 ◽

Vol 66 (01) ◽

pp. 049-061 ◽

Cited By ~ 233

Author(s):

Björn Dahlbäck

Keyword(s):

Vitamin K ◽

Complement System ◽

Protein C ◽

Protein S ◽

High Affinity ◽

Anticoagulant System ◽

Dependent Protein ◽

The Complement System ◽

Β Chain ◽

Dependent Domain

SummaryThe protein C anticoagulant system provides important control of the blood coagulation cascade. The key protein is protein C, a vitamin K-dependent zymogen which is activated to a serine protease by the thrombin-thrombomodulin complex on endothelial cells. Activated protein C functions by degrading the phospholipid-bound coagulation factors Va and VIIIa. Protein S is a cofactor in these reactions. It is a vitamin K-dependent protein with multiple domains. From the N-terminal it contains a vitamin K-dependent domain, a thrombin-sensitive region, four EGF)epidermal growth factor (EGF)-like domains and a C-terminal region homologous to the androgen binding proteins. Three different types of post-translationally modified amino acid residues are found in protein S, 11 γ-carboxy glutamic acid residues in the vitamin K-dependent domain, a β-hydroxylated aspartic acid in the first EGF-like domain and a β-hydroxylated asparagine in each of the other three EGF-like domains. The EGF-like domains contain very high affinity calcium binding sites, and calcium plays a structural and stabilising role. The importance of the anticoagulant properties of protein S is illustrated by the high incidence of thrombo-embolic events in individuals with heterozygous deficiency. Anticoagulation may not be the sole function of protein S, since both in vivo and in vitro, it forms a high affinity non-covalent complex with one of the regulatory proteins in the complement system, the C4b-binding protein (C4BP). The complexed form of protein S has no APC cofactor function. C4BP is a high molecular weight multimeric protein with a unique octopus-like structure. It is composed of seven identical α-chains and one β-chain. The α-and β-chains are linked by disulphide bridges. The cDNA cloning of the β-chain showed the α- and β-chains to be homologous and of common evolutionary origin. Both subunits are composed of multiple 60 amino acid long repeats (short complement or consensus repeats, SCR) and their genes are located in close proximity on chromosome 1, band 1q32. Available experimental data suggest the β-chain to contain the single protein S binding site on C4BP, whereas each of the α-chains contains a binding site for the complement protein, C4b. As C4BP lacking the β-chain is unable to bind protein S, the β-chain is required for protein S binding, but not for the assembly of the α-chains during biosynthesis. Protein S has a high affinity for negatively charged phospholipid membranes, and is instrumental in binding C4BP to negatively charged phospholipid. This constitutes a novel mechanism for control of the complement system on phospholipid surfaces. Recent findings have shown circulating C4BP to be involved in yet another calcium-dependent protein-protein interaction with a protein known as the serum amyloid P-component (SAP). The binding sites on C4BP for protein S and SAP are independent. SAP, which is a normal constituent in plasma and in tissue, is a so-called pentraxin being composed of 5 non-covalently bound 25 kDa subunits. It is homologous to C reactive protein (CRP) but its function is not yet known. The specific high affinity interactions between protein S, C4BP and SAP suggest the regulation of blood coagulation and that of the complement system to be closely linked.

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Molecular Forms of Human Protein C: Comparison and Distribution in Human Adult Plasma

Thrombosis and Haemostasis ◽

10.1055/s-0038-1651025 ◽

1989 ◽

Vol 62 (03) ◽

pp. 902-905 ◽

Cited By ~ 8

Author(s):

Brian S Greffe ◽

Marilyn J Manco-Johnson ◽

Richard A Marlar

Keyword(s):

Heavy Chain ◽

Protein C ◽

Molecular Forms ◽

Post Translational Modification ◽

Single Chain ◽

Beta Form ◽

Sds Page ◽

Dependent Protein ◽

Adult Plasma ◽

The Difference

SummaryProtein C (PC) is a vitamin K-dependent protein which functions as both an anticoagulant and profibrinolytic. It is synthesized as a single chain protein (SC-PC) and post-transla-tionally modified into a two chain form (2C-PC). Two chain PC consists of a light chain (LC) and a heavy chain (HC). The present study was undertaken to determine the composition of the molecular forms of PC in plasma. PC was immunoprecipitated, subjected to SDS-PAGE and Western blotting. The blots were scanned by densitometry to determine the distribution of the various forms. The percentage of SC-PC and 2C-PC was found to be 10% and 90% respectively. This is in agreement with previous work. SC-PC and the heavy chain of 2C-PC consisted of three molecular forms (“alpha”, “beta”, and “gamma”). The “alpha” form of HC is the standard 2C form with a MW of 40 Kd. The “beta” form of HC has also been described and has MW which is 4 Kd less than the “alpha” form. The “gamma” species of the SC and 2C-PC has not been previously described. However, its 3 Kd difference from the “beta” form could be due to modification of the “beta” species or to a separate modification of the alpha-HC. The LC of PC was shown to exist in two forms (termed form 1 and form 2). The difference between these two forms is unknown. The molecular forms of PC are most likely due to a post-translational modification (either loss of a carbohydrate or a peptide) rather than from plasma derived degradation.

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