The Arabidopsis Calcium Sensor Calcineurin B-Like 3 Inhibits the 5′-Methylthioadenosine Nucleosidase in a Calcium-Dependent Manner
| Autor: | Sunhee Yoon, Migyeong Ryu, Jeong-Kook Kim, Jimyeong Park, Seung-Ick Oh, Soojin Park, Sung Han Ok, Yungyeong Kim, Min Jung Nam, Kyung-Nam Kim, Jeong Sheop Shin |
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| Rok vydání: | 2008 |
| Předmět: |
Physiology
Recombinant Fusion Proteins Green Fluorescent Proteins Molecular Sequence Data Arabidopsis chemistry.chemical_element Plant Science Calcium Biology Serine Methylthioadenosine nucleosidase Two-Hybrid System Techniques Onions Protein Interaction Mapping Genetics Arabidopsis thaliana Amino Acid Sequence Calcium Signaling Threonine Glucuronidase Calcium signaling Arabidopsis Proteins Kinase Calcium-Binding Proteins biology.organism_classification Purine-Nucleoside Phosphorylase chemistry Biochemistry Sequence Alignment Research Article |
| Zdroj: | Plant Physiology. 148:1883-1896 |
| ISSN: | 1532-2548 |
| Popis: | Calcineurin B-like (CBL) proteins represent a unique family of calcium sensors in plant cells. Sensing the calcium signals elicited by a variety of abiotic stresses, CBLs transmit the information to a group of serine/threonine protein kinases (CBL-interacting protein kinases [CIPKs]), which are currently known as the sole targets of the CBL family. Here, we report that the CBL3 member of this family has a novel interaction partner in addition to the CIPK proteins. Extensive yeast two-hybrid screenings with CBL3 as bait identified an interesting Arabidopsis (Arabidopsis thaliana) cDNA clone (named AtMTAN, for 5′-methylthioadenosine nucleosidase), which encodes a polypeptide similar to EcMTAN from Escherichia coli. Deletion analyses showed that CBL3 utilizes the different structural modules to interact with its distinct target proteins, CIPKs and AtMTAN. In vitro and in vivo analyses verified that CBL3 and AtMTAN physically associate only in the presence of Ca2+. In addition, we empirically demonstrated that the AtMTAN protein indeed possesses the MTAN activity, which can be inhibited specifically by Ca2+-bound CBL3. Overall, these findings suggest that the CBL family members can relay the calcium signals in more diverse ways than previously thought. We also discuss a possible mechanism by which the CBL3-mediated calcium signaling regulates the biosynthesis of ethylene and polyamines, which are involved in plant growth and development as well as various stress responses. |
| Databáze: | OpenAIRE |
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