LYK4 (At2g23770, O64825) notes

Sources

• UniProt O64825; GOA (19 rows); deep research LYK4-deep-research-falcon.md.
• Cached papers: PMID:22744984 (Wan 2012; Discussion/Conclusion in full text, no Results), PMID:25340959 (Cao 2014, full text), PMID:31270545 (Xue 2019, abstract only), PMID:32284410 (Cheval 2020, full text).

Identity and domains

• Signal peptide 1-22, extracellular 23-275 with 3 LysM motifs, TM 276-296, cytoplasmic kinase-like domain (UniProt).
• Pseudokinase: PMID:22744984; PMID:22744984.
• So kinase activity IEAs (InterPro, EC, Rhea) are removed; ATP binding marked over-annotated (same as LYK5).

Chitin perception

• Chitin-bead pull-down: PMID:22744984. Weak competition: PMID:25340959. No Kd for LYK4.
• Redundancy with LYK5: PMID:25340959.
• Complex: PMID:25340959; PMID:31270545.
• MF choice: coreceptor activity (GO:0015026) proposed NEW rather than PRR activity (GO:0038187, used for LYK5 and for the LYK4/LYK5 family annoton in modules/chitin_perception.yaml). Rationale: authors call LYK4 a co-receptor/scaffold; LYK5 is the main binder. Flagged as a question.

Bacterial response

• lyk4 more susceptible to Pst DC3000, but PMID:22744984; bacterial ligand only speculated. GO:0071219 rows (IBA, IEP) marked over-annotated.

Plasmodesmata

• PMID:32284410; PMID:32284410. CERK1 is not required for this branch. Added plasmodesma (GO:0009506) as NEW location. No regulation-of-plasmodesmal-transport GO term exists (see LYM2 review proposal).

Other

• Chloroplast ISM removed (signal peptide misread).
• Erwig 2017 (PMID:28513921) abstract concerns LYK5/CERK1 only; deep research claims LYK4 is trans-phosphorylated by CERK1 and CPK5/6, not verifiable from cached abstracts, so not used.