The histidine kinase-related domain participates in phytochrome B function but is dispensable

AUTOR(ES)

Krall, Leonard

FONTE

The National Academy of Sciences

RESUMO

Phytochromes are photoreceptors that control many plant light responses. Phytochromes have two carboxyl-terminal structural domains called the PAS repeat domain and the histidine kinase-related domain. These domains are each related to bacterial histidine kinase domains, and biochemical studies suggest that phytochromes are light-regulated kinases. The PAS repeat domain is important for proper phytochrome function and can interact with putative signaling partners. We have characterized several new phytochrome B mutants in Arabidopsis that express phyB protein, three of which affect the histidine kinase-related domain. Point mutations in the histidine kinase-related domain cause phenotypes similar to those of null mutants, indicating that this domain is important for phyB signaling. However, a truncation that removes most of the histidine kinase-related domain results in a phyB molecule with partial activity, suggesting that this domain is dispensable. These results suggest that phytochromes evolved in modular fashion. We discuss possible functions of the histidine kinase-related domain in phytochrome signaling.

Documentos Relacionados

• RYK, a receptor tyrosine kinase-related molecule with unusual kinase domain motifs.
• Regulated Expression of Focal Adhesion Kinase-Related Nonkinase, the Autonomously Expressed C-Terminal Domain of Focal Adhesion Kinase
• A protein kinase-related gene within the channel catfish herpesvirus genome.
• Lymphocyte antigen receptor activation of a focal adhesion kinase-related tyrosine kinase substrate.
• Interleukin-2 induces β2-integrin-dependent signal transduction involving the focal adhesion kinase-related protein B (fakB)