NORK (DMI2 / MtSYMRK), Medicago truncatula, Q8L4H4: notes
Sources
- UniProt Q8L4H4 (Swiss-Prot). Falcon deep research (
NORK-deep-research-falcon.md).
- Cached PMIDs. Only 28267253 and 11006338 have full text; the others are abstract-only.
Identity and architecture
- Signal peptide 1-29, malectin-like domain, 4 LRRs (408-500), TM 522-542, kinase domain 596-873 (UniProt).
- PMID:12087406. Cloned from M. sativa, with M. truncatula alleles.
- Lotus/pea ortholog SYMRK: PMID:12087405.
Genetics: both symbioses
- PMID:11006338
- PMID:11078514 So DMI2 acts upstream of calcium spiking, while DMI3 acts downstream of it.
- Nodules: PMID:16006515
- The two roles are separable. The G795E (dmi2-4/R38) allele is Nod- but Myc+ (UniProt MUTAGEN, from PMID:12087406), and that variant is kinase-dead: PMID:28267253. So kinase activity is needed for nodulation but apparently not for AM. This is important for keeping the nodulation and AM terms distinct.
Biochemistry
- PMID:28267253; NORK phosphorylates kinase-dead LYK3 on Ser269/273/307/323/471. LYK3 did not phosphorylate NORK.
- PUB1 (E3 ligase) is an interactor and in vitro substrate: PMID:26839127. According to the deep research summary, PUB1 did not ubiquitinate DMI2.
- HMGR1 interacts with the active kinase domain PMID:18156218 but is not a demonstrated substrate.
- No ligand has been identified for the ectodomain.
Localisation
Curation decisions
- All kinase MF annotations (IDA, EXP, and the IEAs) were accepted. Core MF is GO:0004674. GO:0004675 (transmembrane receptor Ser/Thr kinase) was not proposed because no ligand is known.
- protein binding (PUB1): changed (MODIFY) to GO:0031625 ubiquitin protein ligase binding.
- NEW annotations: GO:0009877 nodulation (IMP), GO:0036377 AM association (IMP), GO:0005886 plasma membrane (IDA).
- Comparator check: LYK3 (Q6UD73) and CCaMK (Q6RET7) carry GO:0009877 by IMP; LYK3 carries plasma membrane by IDA. NORK lacking these terms is a gap, not a convention.
- Participation check: NORK is an active signalling kinase in the pathway, not a substrate.
- No defense terms are present. No ligand-binding or receptor-activity terms were proposed.