Involvement of specific calmodulin isoforms in salicylic acid-independent activation of plant disease resistance responses

Heo, Won Do; Lee, S.H.; Kim, Min Chul; Kim, Jong Cheol; Chung, Woo Sik; Chun, Hyun Jin; Lee, Kyoung Joo; Park, Chan Young; Park, Hyeong Cheol; Choi, Ji Young; Cho, Moo Je

doi:10.1073/pnas.96.2.766

Cited by 241 publications

(187 citation statements)

References 49 publications

Supporting

Mentioning

175

Contrasting

Unclassified

Order By: Relevance

“…For mannitol treatment, 1 M mannitol solution dissolved in KN-1 medium was added to make a final concentration of 200 mM. The fungal elicitor was prepared from Fusarium solani grown on potato dextrose agar (Difco) medium as described (Heo et al, 1999); the elicitor was carefully added into the flask of the cultured SB-P cells at a final total reducing sugar concentration of 50 g/mL. A 32 P-labeled 642-bp ApaI fragment including the 3Ј untranslated regions of SCA1 cDNA was used as a gene-specific probe.…”

Section: Rna Gel Blot Analysesmentioning

confidence: 99%

Identification of a Calmodulin-Regulated Soybean Ca²⁺-ATPase (SCA1) That Is Located in the Plasma Membrane

et al. 2000

Self Cite

View full text Add to dashboard Cite

Ca 2 ؉ -ATPases are key regulators of Ca 2 ؉ ion efflux in all eukaryotes. Animal cells have two distinct families of Ca 2 ؉ pumps, with calmodulin-stimulated pumps (type IIB pumps) found exclusively at the plasma membrane. In plants, no equivalent type IIB pump located at the plasma membrane has been identified at the molecular level, although related isoforms have been identified in non-plasma membrane locations. Here, we identify a plant cDNA, designated SCA1 (for soybean Ca 2 ؉ -ATPase 1), that encodes Ca 2 ؉ -ATPase and is located at the plasma membrane. The plasma membrane localization was determined by sucrose gradient and aqueous two-phase membrane fractionations and was confirmed by the localization of SCA1p tagged with a green fluorescent protein. The Ca 2 ؉ -ATPase activity of the SCA1p was increased approximately sixfold by calmodulin ( K 1/2 ‫ف‬ 10 nM). Two calmodulin binding sequences were identified in the N-terminal domain. An N-terminal truncation mutant that deletes sequence through the two calmodulin binding sites was able to complement a yeast mutant (K616) that was deficient in two endogenous Ca 2 ؉ pumps. Our results indicate that SCA1p is structurally distinct from the plasma membrane-localized Ca 2 ؉ pump in animal cells, belonging instead to a novel family of plant type IIB pumps found in multiple subcellular locations. In plant cells from soybean, expression of this plasma membrane pump was highly and rapidly induced by salt (NaCl) stress and a fungal elicitor but not by osmotic stress. INTRODUCTIONCa 2 ϩ plays a central role as a second messenger in signal transduction of all eukaryotes (Bootman and Berrige, 1995;Clapham, 1995). The transient increase of cytosolic free Ca 2 ϩ concentration, [Ca 2 ϩ ] cyt , is correlated with a variety of external signals such as touch, temperature shift, abscisic acid, auxin, red light, fungal elicitors, salinity/drought, anoxia, gravity, gibberellic acid, cytokinin, oxidative stress, and hypoxia (Bush, 1995; Sanders et al., 1999). In turn, the increased [Ca 2 ϩ ] cyt triggers many signal transduction pathways, including the regulation of enzyme activity, ion channel activity, and gene expression, which results in diverse cellular responses (Bush, 1995). In addition to its role as a second messenger, Ca 2 ϩ also is important in regulating the processing of proteins in secretory pathways (Rudolph et al., 1989). Thus, cells require carefully regulated transport systems to control [Ca 2 ϩ ] in the cytoplasm and endomembrane compartments. Influx of Ca 2 ϩ to the cytosol occurs as a "downhill" transport through Ca 2 ϩ channels (Sanders et al., 1999). In contrast, the efflux of Ca 2 ϩ from the cytosol is mediated by two active Ca 2 ϩ transporters-Ca 2 ϩ pumps and Ca 2 ϩ /H ϩ antiporters-which are powered by ATP hydrolysis and proton motive force, respectively (Bush, 1995). In plants, Ca 2 ϩ -ATPases are believed to be a major Ca 2 ϩ transporter for the endoplasmic reticulum (ER), Golgi apparatus, vacuole, plastid inner membrane, and plasma membrane (Sander...

show abstract

Section: Rna Gel Blot Analysesmentioning

confidence: 99%

Identification of a Calmodulin-Regulated Soybean Ca²⁺-ATPase (SCA1) That Is Located in the Plasma Membrane

et al. 2000

Self Cite

View full text Add to dashboard Cite

show abstract

“…The opposite is true for mammalian nitric-oxide synthase (23,24). Furthermore, specific CaM isoform(s) mediate SA-independent plant defense signal transduction in vivo (20), although the exact defense signaling cascades mediated by the CaM isoforms remain to be elucidated. There is considerable interest in identifying and characterizing CaM-binding proteins because at least some are expected to have a direct role in mediating the outcome of plant-pathogen encounters.…”

mentioning

confidence: 99%

“…In plant cells, multiple CaM genes exist that code for numerous CaM isoforms in wheat (16), potato (17), Arabidopsis (18), and soybean (19). Expression of CaM isoform genes is differentially induced in response to physical and chemical stimuli, including pathogen invasion (20). CaM isoforms have been found to regulate differentially many Ca 2ϩ / CaM-dependent enzymes in vitro (21).…”

mentioning

confidence: 99%

Mlo, a Modulator of Plant Defense and Cell Death, Is a Novel Calmodulin-binding Protein

Kim

Lee

Kim

et al. 2002

Journal of Biological Chemistry

Self Cite

138

102

View full text Add to dashboard Cite

Transient influx of Ca2؉ constitutes an early event in the signaling cascades that trigger plant defense responses. However, the downstream components of defense-associated Ca 2؉ signaling are largely unknown. Because Ca 2؉ signals are mediated by Ca 2؉ -binding proteins, including calmodulin (CaM), identification and characterization of CaM-binding proteins elicited by pathogens should provide insights into the mechanism by which Ca 2؉ regulates defense responses. In this study, we isolated a gene encoding rice Mlo (Oryza sativa Mlo; OsMlo) using a protein-protein interactionbased screening of a cDNA expression library constructed from pathogen-elicited rice suspension cells. OsMlo has a molecular mass of 62 kDa and shares 65% sequence identity and scaffold topology with barley Mlo, a heptahelical transmembrane protein known to function as a negative regulator of broad spectrum disease resistance and leaf cell death. By using gel overlay assays, we showed that OsMlo produced in Escherichia coli binds to soybean CaM isoform-1 (SCaM-1) in a Ca 2؉ -dependent manner. We located a 20-amino acid CaMbinding domain (CaMBD) in the OsMlo C-terminal cytoplasmic tail that is necessary and sufficient for Ca 2؉ -dependent CaM complex formation. Specific binding of the conserved CaMBD to CaM was corroborated by sitedirected mutagenesis, a gel mobility shift assay, and a competition assay with a Ca 2؉ /CaM-dependent enzyme. Expression of OsMlo was strongly induced by a fungal pathogen and by plant defense signaling molecules. We propose that binding of Ca 2؉ -loaded CaM to the C-terminal tail may be a common feature of Mlo proteins.

show abstract

“…In particular in tobacco the three CAM isoforms NtCAM1, NtCAM3 and NtCAM13 have been shown to bind to the calcium-binding protein kinase NtCBK2 with different affinities and to modulate differently its enzymatic activity (Hua et al 2003). In soybean the two divergent CAM isoforms CAM4 and CAM5, but not the other CAMs which are highly conserved, are involved in disease resistance responses (Heo et al 1999), while the isoforms CAM1 and CAM4 differentially regulate the DNA binding activity of the AtMYB2 transcription factor (Yoo et al 2005).…”

Section: Introductionmentioning

confidence: 99%

A loss-of-function mutation in Calmodulin2 gene affects pollen germination in Arabidopsis thaliana

et al. 2010

View full text Add to dashboard Cite

Calmodulin (CAM) is an ubiquitous calcium binding protein whose function is to translate the signals, perceived as calcium concentration variations, into the appropriate cellular responses. In Arabidopsis thaliana there are 4 CAM isoforms which are highly similar, encoded by 7 genes, and one possible explanation proposed for the evolutionary conservation of the CAM gene family is that the different genes have acquired different functions so that they play possibly overlapping but non-identical roles. Here we report the characterization of the Arabidopsis mutant cam2-2, identified among the lines of the gene-trapping collection EXOTIC because of a distorted segregation of kanamycin resistance. Phenotypic analysis showed that in normal growth conditions cam2-2 plants were indistinguishable from the wild type while genetic analysis showed a reduced transmission of the cam2-2 allele through the male gametophyte and in vitro pollen germination revealed a reduced level of germination in comparison with the wild type. These results provide genetic evidence of the involvement of a CAM gene in pollen germination and support the theory of functional diversification of the CAM gene family.

show abstract

Involvement of specific calmodulin isoforms in salicylic acid-independent activation of plant disease resistance responses

Cited by 241 publications

References 49 publications

Identification of a Calmodulin-Regulated Soybean Ca²⁺-ATPase (SCA1) That Is Located in the Plasma Membrane

Identification of a Calmodulin-Regulated Soybean Ca²⁺-ATPase (SCA1) That Is Located in the Plasma Membrane

Mlo, a Modulator of Plant Defense and Cell Death, Is a Novel Calmodulin-binding Protein

A loss-of-function mutation in Calmodulin2 gene affects pollen germination in Arabidopsis thaliana

Contact Info

Product

Resources

About

Involvement of specific calmodulin isoforms in salicylic acid-independent activation of plant disease resistance responses

Cited by 241 publications

References 49 publications

Identification of a Calmodulin-Regulated Soybean Ca2+-ATPase (SCA1) That Is Located in the Plasma Membrane

Identification of a Calmodulin-Regulated Soybean Ca2+-ATPase (SCA1) That Is Located in the Plasma Membrane

Mlo, a Modulator of Plant Defense and Cell Death, Is a Novel Calmodulin-binding Protein

A loss-of-function mutation in Calmodulin2 gene affects pollen germination in Arabidopsis thaliana

Contact Info

Product

Resources

About

Identification of a Calmodulin-Regulated Soybean Ca²⁺-ATPase (SCA1) That Is Located in the Plasma Membrane

Identification of a Calmodulin-Regulated Soybean Ca²⁺-ATPase (SCA1) That Is Located in the Plasma Membrane