CRN (CORYNE / SOL2, At5g13290; UniProt Q9LYU7) curation notes

Identity

• SOL2 was identified from a root CLE19 suppressor screen, and CRN from shoot genetics. They are the same gene PMID:18854335.
• UniProt Q9LYU7 is "Inactive leucine-rich repeat receptor-like protein kinase CORYNE". The SOL2 symbol also collides with TCX2 (At4g14770); the correct entry was verified by AGI locus.
• The protein has a short extracellular region, one TM helix, and a kinase-like domain. The deep research (falcon) confirms the "short extracellular segment rather than an extracellular leucine-rich-repeat binding domain".

Pseudokinase

• The catalytic loop is HYN instead of HRD, and the G-loop is GXDXXG. There is no in vitro autophosphorylation, and kinase-dead K146E complements crn-1 PMID:21398569.
• The kinase-like domain is still needed for SAM signalling but not in the root PMID:27229734.
• Decisions: the NOT protein kinase activity row is ACCEPTED. The IEA ATP binding is REMOVED, because the degenerate G-loop is predicted to inhibit ATP binding and no binding has been shown.

Complex and trafficking

• CRN binds CLV2 via TM/juxtamembrane contacts, and the two require each other for ER export PMID:19933383.
• It interacts weakly with CLV1 PMID:19843317, and with CIK1-4 PMID:29581511 and MAZZA PMID:33909893.
• In roots, CRN stabilizes BAM3 PMID:28607033.

Core MF choice

• Signaling receptor complex adaptor activity (GO:0030159). It reflects the scaffold role suggested by Nimchuk 2011 PMID:21398569 and the BAM3 stabilization.
• The IMP peptide receptor activity is MODIFIED to this term, because CRN has no ligand-binding ectodomain.

Removed

• Mitochondrion (ISM), which is contradicted by the experimental plasma membrane and ER localization.