The kinase LYK5 is a major chitin receptor in Arabidopsis and forms a chitin-induced complex with related kinase CERK1
- University of Missouri, United States
- Argonne National Laboratory, United States
Figures
Figure 1 with 5 supplements
Atlyk5 mutant plants are defective in chitin-triggered immune responses.
(A) ROS production was measured from Col-0 wild-type and Atlyk5-2 mutant plants for 30 min after treatment with different chitin oligomers. 5mer: chitopentaose, 6mer: chitohexaose, 7mer: …
Figure 1—figure supplement 1
Arabidopsis LYK gene family.
A complete alignment based on the full-length sequences of each protein was used to draw the phylogenetic tree using Clustal X software. AtCERK1: At3g21630, AtLYK2: At3g01840, AtLYK3: At1g51940, …
Figure 1—figure supplement 2
Chitin response in Ler lyk5-1 mutant plants.
(A–B) WRKY53 gene (A) and WRKY33 gene (B) expression was analyzed using qRT-PCR in Ler wild-type and Atlyk5-1 mutant plants with or without treatment with 1 µM chitooctaose. 8mer: chitooctaose. Data …
Figure 1—figure supplement 3
Characterization of Atlyk5 mutant plants.
(A) Genomic structure of AtLYK5 and two insertion sites of two mutants. (B) Identification of T-DNA insertion by PCR using genomic DNA from Col-0 wild-type and Atlyk5-2 mutant plants. Location of …
Figure 1—figure supplement 4
WRKY33 and WRKY53 gene expression in Atlyk5-2 mutant plants.
(A) Calcium influx in the wild-type, Atcerk1 and Atlyk5-2 mutant plants expressing aequorin was recorded for 30 min after 100 nM flg22 treatment. (B) WRKY33 (At2g38470) and (C) WRKY53 (At4g23810) …
Figure 1—figure supplement 5
Chitin-induced ROS production in five lyk mutant plants.
ROS production was measured from Col-0 wild-type, five Atlyk mutant, and Atlyk4/Atlyk5-2 double mutant plants for 30 min after treatment with 1 µM chitooctaose. Data are mean ± SE (n = 8). Asterisks …
Figure 2 with 2 supplements
AtLYK5 has overlapping function with AtLYK4.
(A) ROS production was measured from Col-0 wild-type, Atyk4, Atlyk5-2, and Atlyk4/lyk5-2 mutant plants for 30 min after treatment with H2O (as control) or 1 µM chiooctaose. 8mer: chitooctaose. Data …
Figure 2—figure supplement 1
Complementation of Atlyk5-2 mutant plants.
(A) HA-tagged AtLYK5 protein levels in different transgenic Atlyk5-2 mutant plants expressing full length AtLYK5 under the control of its native promoter. (B) ROS production was measured from the …
Figure 2—figure supplement 2
Tissue-specific expression of AtCERK1, AtLYK4, and AtLYK5.
(A) AtCERK1 (At3g21630), AtLYK4 (At2g23770) and AtLYK5 (At2g33580) gene expression in different developmental stages predicted by AtGenExpress Visualization Tool (AVT) . Results can also be seen at h…
Figure 3 with 1 supplement
AtLYK5 shows stronger chitin binding affinity than AtCERK1.
The binding affinity of AtLYK5 (A) and AtCERK1 (B) to chitooctaose (GlcNAc)8 was measured using isothermal titration calorimetry (ITC). Proteins were purified from E. coli. Upper panels and lower …
Figure 3—figure supplement 1
AtLYK5 has chitooctaose binding affinity.
(A) Chitin binding of AtLYK proteins detected using chitin-magnetic beads. HA-tagged AtCERK1 and AtLYK2-5 were expressed from the 35S promoter in protoplasts made from Col-0 wild type plants. …
Figure 4 with 1 supplement
Tyr-128 and Ser-206 are important for AtLYK5-mediated chitin response.
(A) A computational ribbon structure of the AtLYK5 ectodomain was built based on crystal structure of fungal ECP6. The model shows the three AtLYK5 LysM domains, i.e. LysM1-3. Each LysM domain …
Figure 4—figure supplement 1
Computational model of the extracellular domain of AtLYK5.
(A–C) The docking model of the ectodomain with chitooctaose shown in surface (A) and ribbon form (B) and a close-up surface (C). The binding affinity was calculated at −8.9 kcal mol−1. The model …
Figure 5 with 1 supplement
AtLYK5 regulates chitin-induced phosphorylation and homodimerization of AtCERK1.
(A) AtLYK5 associates with AtCERK1 after chitin treatments. HA-tagged AtCERK1 and Myc-tagged AtLYK5 or AtCERK1 were co-expressed in protoplasts made from Col-0 wild-type plants. Protoplasts were …
Figure 5—figure supplement 1
AtLYK4 associates with AtCERK1 before and after chitin treatment.
(A) Interaction between AtCERK1 and AtLYK4. HA-tagged AtCERK1 and Myc-tagged AtLYK4 were co-expressed in protoplasts from Col-0 wild type plants. Protoplasts either prior (−) or after treatment with …
Figure 6 with 1 supplement
The kinase domain of AtLYK5 is critical for chitin signaling.
(A) In vitro kinase activities of AtCERK1 (255–617 aa) and AtLYK5 (309–664 aa) were measured by incorporation of γ-[32P]-ATP. Left panel shows autoradiography, and right panel shows gel stained with …
Figure 6—figure supplement 1
AtLYK5 is a kinase inactive protein.
(A) AtLYK5 lacks conserved residues required for kinase activity. Sequence alignment was done using the entire intracellular domain of AtLYK5 and other, selected receptor kinases. Each kinase …
Figure 7 with 1 supplement
AtLYK5 forms a homodimer.
(A) Homodimeriztion of AtLYK5 is independent on the presence of CERK1 or chitin elicitation. AtLYK5-HA and AtLYK5-Myc, or AtCERK1-HA and AtCERK1-Myc were co-expressed in protoplasts made from Col-0 …
Figure 7—figure supplement 1
A possible working model of chitin receptor in Arabidopsis.
Before chitin treatment, AtLYK5 is present as a homodimer. After chitin elicitation, AtCERK1 associates with AtLYK5 to form a possible tetremer to mediate chitin signaling, and AtCERK1 will be …
Additional files
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Supplementary file 1
Primer sequences used in this study.
- https://doi.org/10.7554/eLife.03766.022
