Methyl-CpG-binding domain (MBD) proteins in plants

2007 ◽  
Vol 1769 (5-6) ◽  
pp. 287-294 ◽  
Author(s):  
Gideon Grafi ◽  
Assaf Zemach ◽  
Letizia Pitto
Keyword(s):  
Binding Domain ◽  
Mbd Proteins

scholarly journals Heterologous Expression of SvMBD5 from Salix viminalis L. Promotes Flowering in Arabidopsis thaliana L.

Genes ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 285
Author(s):  
Yunhe Cheng ◽  
Lili Cheng ◽  
Qingchang Cao ◽  
Junzhu Zou ◽  
Xia Li ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Dna Demethylation ◽  
Binding Domain ◽  
Salix Viminalis ◽  
Flowering Genes ◽  
Acid Protein ◽  
Localization Analysis ◽  
Model Plant Arabidopsis Thaliana ◽  
Flowering Locus ◽  
Mbd Proteins

Methyl-CpG-binding domain (MBD) proteins have diverse molecular and biological functions in plants. Most studies of MBD proteins in plants have focused on the model plant Arabidopsis thaliana L. Here we cloned SvMBD5 from the willow Salix viminalis L. by reverse transcription-polymerase chain reaction (RT-PCR) and analyzed the structure of SvMBD5 and its evolutionary relationships with proteins in other species. The coding sequence of SvMBD5 is 645 bp long, encoding a 214 amino acid protein with a methyl-CpG-binding domain. SvMBD5 belongs to the same subfamily as AtMBD5 and AtMBD6 from Arabidopsis. Subcellular localization analysis showed that SvMBD5 is only expressed in the nucleus. We transformed Arabidopsis plants with a 35S::SvMBD5 expression construct to examine SvMBD5 function. The Arabidopsis SvMBD5-expressing line flowered earlier than the wild type. In the transgenic plants, the expression of FLOWERING LOCUS T and CONSTANS significantly increased, while the expression of FLOWERING LOCUS C greatly decreased. In addition, heterologously expressing SvMBD5 in Arabidopsis significantly inhibited the establishment and maintenance of methylation of CHROMOMETHYLASE 3 and METHYLTRANSFERASE 1, as well as their expression, and significantly increased the expression of the demethylation-related genes REPRESSOR OF SILENCING1 and DEMETER-LIKE PROTEIN3. Our findings suggest that SvMBD5 participates in the flowering process by regulating the methylation levels of flowering genes, laying the foundation for further studying the role of SvMBD5 in regulating DNA demethylation.

NMR studies of the R2 repeat and related peptide fragments of the DNA binding domain of c-Myb. New light on the structure and folding of R2.

1999 ◽  
Vol 96 (9/10) ◽  
pp. 1580-1584 ◽  
Author(s):  
I. Ségalas ◽  
S. Desjardins ◽  
H. Oulyadi ◽  
Y. Prigent ◽  
S. Tribouillard ◽  
...  
Keyword(s):  
Dna Binding ◽  
Binding Domain ◽  
Dna Binding Domain ◽  
Peptide Fragments ◽  
Nmr Studies ◽  
Related Peptide

Limited Proteolysis of Vitronectin by Plasmin Destroys Heparin Binding Activity

1991 ◽  
Vol 66 (03) ◽  
pp. 310-314 ◽  
Author(s):  
David C Sane ◽  
Tammy L Moser ◽  
Charles S Greenberg
Keyword(s):  
Limited Proteolysis ◽  
Plasminogen Activator Inhibitor ◽  
Binding Activity ◽  
Binding Domain ◽  
Heparin Binding ◽  
Inhibitor Type ◽  
Activator Inhibitor Type ◽  
Activator Inhibitor ◽  
Pai 1

SummaryVitronectin (VN) stabilizes plasminogen activator inhibitor type 1 (PAI-1) activity and prevents the fibrin(ogen)-induced acceleration of plasminogen activation by t-PA. These antifibrinolytic activities as well as other functions are mediated by the glycosaminoglycan (GAG) binding domain of VN. Since the GAG binding region is rich in arginyl and lysyl residues, it is a potential target for enzymes such as plasmin. In this paper, the dose and time-dependent proteolysis of VN by plasmin is demonstrated. The addition of urokinase or streptokinase (200 units/ml) to plasma also produced proteolysis of VN. With minimal proteolysis, the 75 kDa band was degraded to a 62-65 kDa form of VN. This minimal proteolysis destroyed the binding of [3H]-heparin to VN and reversed the neutralization of heparin by VN.Thus, the plasmin-mediated proteolysis of the GAG binding activity of VN could destroy the antifibrinolytic activity of VN during physiologic conditions and during thrombolytic therapy. Furthermore, other functions of VN in complement and coagulation systems that are mediated by the GAG binding domain may be destroyed by plasmin proteolysis.

Ristocetin and Botrocetin Involve Two Distinct Domains of von Willebrand Factor for Binding to Platelet Membrane Glycoprotein lb

1990 ◽  
Vol 64 (02) ◽  
pp. 326-332 ◽  
Author(s):  
J P Girma ◽  
Y Takahashi ◽  
A Yoshioka ◽  
J Diaz ◽  
D Meyer
Keyword(s):  
Von Willebrand Factor ◽  
Synthetic Peptides ◽  
Competitive Inhibition ◽  
Final Concentration ◽  
Binding Domain ◽  
Platelet Membrane ◽  
Platelet Glycoprotein ◽  
Membrane Glycoprotein ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryWe have evidence that ristocetin and botrocetin mediate binding of von Willebrand Factor (vWF) to platelet glycoprotein lb (GPIb) through two distinct domains on the vWF molecule. This was established by using monoclonal antibodies (MAbs) to vWF and synthetic peptides derived from the sequence of vWF. MAb 322 and MAb NMC/vW 4 both recognize native vWF as well as fragments containing the GPIb-binding domain of vWF, obtained with the following enzymes: trypsin (116 kDa), V-8 pro tease (Spill, 320 kDa) and V-8 protease plus subtilisin (33-28 kDa). Nevertheless, the lack of reciprocal displacement between the two MAbs in experiments of competitive inhibition for binding to vWF demonstrate that their respective epitopes are separate. Both MAbs inhibit 125I-vWF binding to platelet membrane GPIb and vWF-dependent platelet agglutination induced by ristocetin. However, only MAb NMC/vW4 inhibits these functions in the presence of botrocetin and when ristocetin-induced platelet agglutination is inhibited by MAb 322, botrocetin is still able to restore the agglutination. The involvement of two distinct domains of vWF for binding to GPIb in the presence of ristocetin or botrocetin was confirmed in experiments of binding of 125I-vWF to platelets using as competitor synthetic peptides corresponding to the GPIb binding domain of vWF (Cys 474 to Pro 488 and Ser 692 to Pro 708). At a final concentration of 2.5 mM both peptides inhibit more than 90% of the binding of vWF to ristocetin-treated platelets but are unable to modify this binding in the presence of botrocetin. In conclusion our data suggest that botrocetin and ristocetin involve distinct sites on vWF for binding to GPIb.

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