With the growing availability of genomic sequence information, there is an increasing need for gene function analysis. Antibody-mediated "silencing" represents an intriguing alternative for the precise inhibition of a particular function of biomolecules. Here, we describe a method for selecting recombinant antibodies with a specific purpose in mind, which is to inhibit intrinsic protein-protein interactions in the cytosol of plant cells. Experimental procedures were designed for conveniently evaluating desired properties of recombinant antibodies in consecutive steps. Our selection method was successfully used to develop a recombinant antibody inhibiting the interaction of ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN 3 with such of its upstream interaction partners as the receiver domain of CYTOKININ INDEPENDENT HISTIDINE KINASE 1. The specific down-regulation of the cytokinin signaling pathway in vivo demonstrates the validity of our approach. This selection method can serve as a prototype for developing unique recombinant antibodies able to interfere with virtually any biomolecule in the living cell.

• MeSH
• Arabidopsis genetika   MeSH
• cytosol imunologie   metabolismus   MeSH
• fosfotransferasy biosyntéza   genetika   imunologie   MeSH
• mapy interakcí proteinů genetika   imunologie   MeSH
• proteinkinasy biosyntéza   genetika   imunologie   MeSH
• proteiny huseníčku biosyntéza   genetika   imunologie   MeSH
• protilátky aplikace a dávkování   imunologie   MeSH
• regulace genové exprese u rostlin MeSH
• rekombinantní proteiny aplikace a dávkování   imunologie   MeSH
• signální transdukce MeSH
• umlčování genů imunologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• AHP3 protein, Arabidopsis MeSH Prohlížeč
• CKI1 protein, Arabidopsis MeSH Prohlížeč
• fosfotransferasy MeSH
• proteinkinasy MeSH
• proteiny huseníčku MeSH
• protilátky MeSH
• rekombinantní proteiny MeSH

Immunodetection is a powerful tool in functional studies of all organisms. In plants, the gene redundancy and presence of gene families composed of highly homologous members often impedes the unambiguous identification of individual gene products. A family of eight sensor histidine kinases (HKs) mediates the transduction of diverse signals into Arabidopsis thaliana cells, thereby ensuring the initiation of appropriate adaptive responses. Antibodies recognizing specific members of the HK family would be valuable for studying their functions in Arabidopsis and other plant species including important crops. We have focused on developing and applying antibodies against CYTOKININ-INDEPENDENT 1 (CKI1), which encodes a constitutively active membrane-bound sensor HK that regulates the development of female gametophytes and vascular tissue in Arabidopsis. A coding sequence delimiting the C-terminal receiver domain of CKI1 (CKI1(RD)) was expressed in Escherichia coli using the IPTG-inducible expression system and purified to give a highly pure target protein. The purified CKI1(RD) protein was then used as an antigen for anti-CKI1(RD) antibody production. The resulting polyclonal antibodies had a detection limit of 10 ng of target protein at 1:20,000 dilution and were able to specifically distinguish CKI1, both in vitro and in situ, even in a direct comparison with highly homologous members of the same HK family AHK4, CKI2 and ETR1. Finally, anti-CKI1(RD) antibodies were able to selectively bind CKI1-GFP fusion protein in a pull-down assay using crude lysate from an Arabidopsis cell suspension culture. Our results suggest that the receiver domain is a useful target for the functional characterization of sensor HKs in immunological and biochemical studies.

• Klíčová slova
• CKI1, Immunolocalization, Immunoprecipitation, Polyclonal antibodies, Receiver domain,
• MeSH
• Arabidopsis cytologie   enzymologie   MeSH
• imunoprecipitace MeSH
• molekulární sekvence - údaje MeSH
• proteinkinasy chemie   imunologie   izolace a purifikace   metabolismus   MeSH
• proteiny huseníčku chemie   imunologie   izolace a purifikace   metabolismus   MeSH
• protilátky imunologie   MeSH
• sekvence aminokyselin MeSH
• signální transdukce MeSH
• specificita protilátek MeSH
• terciární struktura proteinů MeSH
• transport proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• CKI1 protein, Arabidopsis MeSH Prohlížeč
• proteinkinasy MeSH
• proteiny huseníčku MeSH
• protilátky MeSH