A Janus kinase participating in cytokine-receptor signalling, including interferon responses relevant to tumour–immune interactions.

A Janus kinase involved in cytokine-receptor signalling, including interferon-gamma responses in relevant cells.

An energy-responsive protein kinase regulated by adenine nucleotide status and upstream inputs. It helps adjust cellular demand and supply when energetic conditions change.

A family of signaling protein kinases downstream of Ras and upstream of MEK in a major growth-regulatory cascade.

A protein kinase participating in distinct regulatory complexes, including mTORC1. Total mTOR abundance and phosphorylation of a specified site are separate measurements.

An oncogenic fusion protein with deregulated tyrosine-kinase activity, classically associated with chronic myeloid leukaemia. Its signalling can be inhibited by drugs including imatinib.

A kinase regulated by cyclic guanosine monophosphate, implicated in several physiological and behavioural processes.

Binding of the cyclic nucleotide changes regulatory interactions and promotes catalytic activity toward selected protein substrates. This couples a second messenger to phosphorylation. A behavioural phenotype involving one family member does not establish an identical role for every cGMP-regulated kinase. ^[ref]

The budding-yeast Polo-like kinase, with multiple mitotic functions including regulation of the Bub2-Bfa1 complex.

A budding-yeast kinase contributing to the spindle position checkpoint through regulation of the Bub2-Bfa1 complex. Its activation and location are both relevant.

A budding-yeast kinase with roles in morphogenesis and cell-cycle regulation, including activation of Kin4.

A polarity-associated kinase. In fly male germline stem cells, it contributes to the centrosome orientation checkpoint and regulation of cyclin A localization.

An atypical protein kinase C is a member of the protein kinase C family whose regulation differs from the conventional calcium- and diacylglycerol-responsive forms. Atypical isoforms participate in signalling and cellular polarity, including complexes with PAR-6. Their name describes a regulatory subfamily; it does not mean that all protein kinase C enzymes share the same activation requirements. ^[ref]

A kinase with an intrinsic calcium-sensing regulatory region. Calcium binding can relieve autoinhibition and couple calcium signaling to substrate phosphorylation.

A plant kinase recruited and regulated by a calcineurin B-like protein. The separate sensor and kinase provide a modular route from calcium signaling to regulation of transport and other targets.

The plant symbiotic kinase CCaMK integrates calcium binding and calmodulin-dependent regulation. Its activation can connect nuclear calcium signaling to symbiotic developmental programs.

Plant sucrose non-fermenting-1-related protein kinase 2 family. Several members mediate abscisic acid responses, including OST1 in guard cells.

A kinase family in Hippo signalling. Phosphorylation of YAP can limit its nuclear transcriptional activity.

Conformational entropy measures the multiplicity of molecular conformations compatible with specified macroscopic constraints. For equally weighted accessible conformations it is $k_B\ln \Omega$; for probabilities $p_i$, it is $-k_B{\sum }_i{p}_i\ln p_i$. A folded protein generally has less chain conformational entropy than its unfolded ensemble, but folding can still lower total Gibbs free energy when solvent and interaction contributions are included.

A folding funnel is a schematic energy landscape in which increasingly native-like protein conformations tend to have lower free energy, while the many unfolded conformations occupy a broad region. Roughness represents barriers and possible kinetic traps. The funnel is an organizing description, not a claim that every protein follows one unique geometrical trajectory or possesses a rigid isolated native state.

A representation of which pairs of residues in a protein are in contact. In a lattice model, nonconsecutive residues may count as contacting when their lattice sites are adjacent. Several geometric foldings can have the same contact map, making it useful for compressing an enumeration of self-avoiding walks.