The minimal, reusable core motif shared by all mitogen-activated protein kinase cascades: a three-tier protein kinase relay in which a MAP kinase kinase kinase (MAP3K) phosphorylates and activates a MAP kinase kinase (MAP2K), which in turn dually phosphorylates the activation loop of a MAP kinase (MAPK). The motif is deliberately gene-free and taxon-neutral: it fixes only the three tier identities (by molecular-function term) and the activating phosphotransfer topology that connects them. Concrete cascades - ERK1/2, p38, JNK, ERK5, the fungal Fus3/Kss1/Hog1 pathways, and plant MPK cascades - embed this motif as an inner bundle through `conforms_to`, substituting their own kinase families and adding their own upstream activation and downstream effector steps before and after the relay. Grounded in GO:0000165 (MAPK cascade).
Reusable conformance target. A node in a concrete cascade module declares `conforms_to: [{template: mapk_relay}]` when its three child steps are an instance of this relay. Conformance is a consistency check, not inheritance: the conforming bundle should contain the three tiers (by molecular-function term GO:0004709 -> GO:0004708 -> GO:0004707) joined by activating (CAUSES) phosphotransfer edges. Legitimate deviations (e.g. a single MAP2K paralog rather than a pair, or a scaffolded relay) may be recorded on the conformance object's `deviations`/`notes` with status WITH_DEVIATIONS rather than forcing a literal structural match. Participants are abstract ANY_WITH_FUNCTION selectors because the motif asserts tier chemistry only; concrete kinase families are supplied by the conforming cascade.
All recommended fields populated.
✗ none found
No MODULE:mapk_relay deep-research report alongside the module YAML.
3 leaf node(s) with no concrete protein grounding:
✓ every declared conforms_to bundle matches its template motif.
No concrete UniProt-grounded genes in this module.
An activated MAP3K phosphorylates serine/threonine residues in the activation loop of a MAP2K. In a concrete cascade this tier is filled by a specific MAP3K family (e.g. RAF for ERK1/2; ASK1/MLK/MEKK for p38 and JNK).
Top tier; phosphorylates and activates the MAP2K.
A dual-specificity MAP2K phosphorylates both the threonine and the tyrosine of the MAPK activation-loop motif. In a concrete cascade this tier is filled by a specific MAP2K family (e.g. MEK1/MEK2 for ERK1/2; MKK3/MKK6 for p38; MKK4/MKK7 for JNK).
Middle tier; dual-specificity activation of the MAPK.
The dually phosphorylated MAPK becomes an active proline-directed serine/threonine kinase that acts on cytoplasmic and nuclear substrates. In a concrete cascade this tier is filled by a specific MAPK family (e.g. ERK1/ERK2; p38 alpha/beta/gamma/delta; JNK1/2/3).
Effector tier; transduces the cascade output to substrates.