scholarly journals A Mechanism for Inhibition of COP1 in Photomorphogenesis: Direct Interactions of Phytochromes with SPA Proteins

2015 ◽  
Vol 27 (1) ◽  
pp. 8-8 ◽  
Author(s):  
Nancy R. Hofmann
Keyword(s):  
Spa Proteins

scholarly journals Genomic evidence reveals SPA-regulated developmental and metabolic pathways in dark-grown Arabidopsis seedlings

2020 ◽  
Author(s):  
Vinh Ngoc Pham ◽  
Inyup Paik ◽  
Ute Hoecker ◽  
Enamul Huq
Keyword(s):  
Transcription Factors ◽  
Light Signaling ◽  
Rna Seq ◽  
Homologous Proteins ◽  
Independent Manner ◽  
Ubiquitin Ligase Complex ◽  
Subsequent Degradation ◽  
Summary Statement ◽  
Genomic Basis ◽  
Spa Proteins

AbstractPhotomorphogenesis is repressed in the dark mainly by an E3 ubiquitin ligase complex comprising CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) and four homologous proteins called SUPPRESSOR OF PHYA-105 (SPA1-SPA4) in Arabidopsis. This complex induces the ubiquitination and subsequent degradation of positively acting transcription factors (e.g., HY5, HFR1, PAP1 and others) in the dark to repress photomorphogenesis. Genomic evidence showed a large number of genes regulated by COP1 in the dark, of which many are direct targets of HY5. However, the genomic basis for the constitute photomorphogenic phenotype of spaQ remains unknown. Here, we show that >7200 genes are differentially expressed in the spaQ background compared to wild-type in the dark. Comparison of the RNA Sequencing (RNA-Seq) data between cop1 and spaQ revealed a large overlapping set of genes regulated by the COP1-SPA complex. In addition, many of the genes coordinately regulated by the COP1-SPA complex are also regulated by HY5 directly and indirectly. Taken together, our data reveal that SPA proteins repress photomorphogenesis by controlling gene expression in concert with COP1, likely through regulating the abundance of downstream transcription factors in light signaling pathways. Moreover, SPA proteins may function both in a COP1-dependent and –independent manner in regulating many biological processes and developmental pathways in Arabidopsis.Summary statementComparison of transcriptome analyses between cop1 and spaQ mutants reveal overlapping pathways regulated by COP1 and SPAs.

scholarly journals Genetic and Antigenic Diversity of the Surface Protective Antigen Proteins of Erysipelothrix rhusiopathiae

2007 ◽  
Vol 14 (7) ◽  
pp. 813-820 ◽  
Author(s):  
Ho To ◽  
Shinya Nagai
Keyword(s):  
Protective Antigen ◽  
Sequence Similarity ◽  
Immunoblot Analysis ◽  
Amino Acid Sequence Similarity ◽  
Potential Candidate ◽  
Erysipelothrix Rhusiopathiae ◽  
Antigenic Diversity ◽  
Reference Strains ◽  
Spa Types ◽  
Spa Proteins

ABSTRACTThe surface protective antigen (Spa) protein ofErysipelothrix rhusiopathiaehas been shown to be highly immunogenic and is a potential candidate for a new vaccine against erysipelas. In this study, we cloned and sequencedspagenes from allE. rhusiopathiaeserovar reference strains as well as from a serovar 18 strain which was not classified as any species in the genusErysipelothrix.Sequence analysis revealed that the Spa proteins could be classified into three molecular species, including SpaA, which was previously found in serovars 1a and 2, and the newly designated SpaB and SpaC proteins. The SpaA protein is produced byE. rhusiopathiaeserovars 1a, 1b, 2, 5, 8, 9, 12, 15, 16, 17, and N, the SpaB protein is produced byE. rhusiopathiaeserovars 4, 6, 11, 19, and 21, and the SpaC protein is produced only by serovar 18. The amino acid sequence similarity was high among members of each Spa type (96 to 99%) but low between different Spa types (∼60%). The greatest diversity in Spa proteins was found in the N-terminal half of the molecule (50 to 57% similarity), which was shown to be involved in immunoprotection. Coinciding with this, immunoblot analysis revealed that rabbit antisera specific to each Spa reacted strongly with the homologous Spa protein but weakly with heterologous Spa proteins. A mouse cross-protection study showed that the three recombinant Spa (rSpa) proteins elicited complete protection against challenge with homologous strains but that the level of protection against challenge with heterologous strains varied depending on the rSpa protein used for immunization. Our study is the first to demonstrate sequence and antigenic diversity in Spa proteins and to indicate that rSpaC may be the most promising antigen for use as a vaccine component because of its broad cross-protectiveness.

scholarly journals Immunization with Truncated Recombinant Protein SpaC of Erysipelothrix rhusiopathiae Strain 715 Serovar 18 Confers Protective Immunity against Challenge with Various Serovars

2010 ◽  
Vol 17 (12) ◽  
pp. 1991-1997 ◽  
Author(s):  
Ho To ◽  
Shuichi Someno ◽  
Shinya Nagai ◽  
Tomohiro Koyama ◽  
Tetsuji Nagano
Keyword(s):  
Protective Immunity ◽  
Protective Antigen ◽  
Protective Efficacy ◽  
Statistical Significance ◽  
Effective Vaccine ◽  
Erysipelothrix Rhusiopathiae ◽  
Helical Domain ◽  
First Time ◽  
Highly Virulent ◽  
Spa Proteins

ABSTRACTPreviously, we showed that surface protective antigen (Spa) proteins ofErysipelothrix rhusiopathiaecan be classified into three molecular species—SpaA, SpaB, and SpaC—and that SpaC is the most broadly cross-protective antigen among the three Spa proteins. In this study, we examined the ability of the α-helical domain, which comprises the N-terminal half of SpaC, to elicit cross-protective immunity in mice and pigs. Mice actively immunized with the full-length protein (rSpaC664) or the α-helical domain (rSpaC427), but not the C-terminal domain (rSpaC253), were protected against challenge withE. rhusiopathiaeserovars 1a, 2, 6, 19, and 18 expressing heterologous (SpaA or SpaB) and homologous (SpaC) Spas. The α-helical domain seemed to provide better protection than rSpaC664, although the differences did not reach statistical significance. Similarly, mice passively immunized with rabbit anti-rSpaC664 or anti-rSpaC427 sera, but not anti-rSpaC253 serum, were protected from challenge with various serovars. Pigs immunized with SpaC427 also developed specific antibodies against Spa proteins and were protected from challenge with the highly virulent heterologousE. rhusiopathiaestrain Fujisawa (serovar 1a). Taken together, these results demonstrate for the first time the striking protective efficacy of the α-helical domain-mediated immunization in both mice and pigs, thereby highlighting its utility as the most promising candidate for the development of a safe and effective vaccine against erysipelas.

scholarly journals SPA Proteins Affect the Subcellular Localization of COP1 in the COP1/SPA Ubiquitin Ligase Complex during Photomorphogenesis

2017 ◽  
Vol 174 (3) ◽  
pp. 1314-1321 ◽  
Author(s):  
Martin Balcerowicz ◽  
Konstantin Kerner ◽  
Christian Schenkel ◽  
Ute Hoecker
Keyword(s):  
Subcellular Localization ◽  
Ubiquitin Ligase ◽  
Ubiquitin Ligase Complex ◽  
Spa Proteins

scholarly journals Degradation of Arabidopsis CRY2 Is Regulated by SPA Proteins and Phytochrome A

2012 ◽  
Vol 24 (6) ◽  
pp. 2610-2623 ◽  
Author(s):  
Guido Weidler ◽  
Sven zur Oven-Krockhaus ◽  
Michael Heunemann ◽  
Christian Orth ◽  
Frank Schleifenbaum ◽  
...  
Keyword(s):  
Phytochrome A ◽  
Spa Proteins

scholarly journals Direct phosphorylation of HY5 by SPA1 kinase to regulate photomorphogenesis in Arabidopsis

2020 ◽  
Author(s):  
Wenli Wang ◽  
Inyup Paik ◽  
Junghyun Kim ◽  
Xilin Hou ◽  
Sibum Sung ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Active Form ◽  
E3 Ubiquitin Ligase ◽  
Kinase Domain ◽  
Ubiquitin Ligase Complex ◽  
The Stability ◽  
Target Promoters ◽  
Spa Proteins

SUMMARYELONGATED HYPOCOTYL5 (HY5) is a key transcription factor which promotes photomorphogenesis by regulating complex downstream growth programs. Previous studies suggest that the regulation of HY5 mainly depends on the CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1) - SUPPRESSOR OF PHYTOCHROME A-105 (SPA) E3 ubiquitin ligase complex, which degrades positively acting transcription factors of light signaling to repress photomorphogenesis in the dark. SPA proteins function not only as a component of the E3 ubiquitin ligase complex but also as a kinase of PHYTOCHROME INTERACTING FACTOR1 (PIF1) through its N-terminal kinase domain. Here, we show that HY5 is a new substrate of SPA1 kinase. SPA1 can directly phosphorylate HY5 in vitro and in vivo. We also demonstrate that unphosphorylated HY5 strongly interacts with both COP1 and SPA1 than phosphorylated HY5, is the preferred substrate for degradation, whereas phosphorylated HY5 is more stable in the dark. In addition, unphosphorylated HY5 actively binds to the target promoters, and is physiologically more active form. Consistently, the transgenic plants expressing unphosphorylated mutant of HY5 displays enhanced photomorphogenesis. Collectively, our study revealed that SPA1 fine-tunes the stability and the activity of HY5 to regulate photomorphogenesis.

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