Serine/threonine-protein kinase Unc-51 (IPR017184)

Short name: Ser/Thr_kinase_Unc51

Family relationships



Protein phosphorylation, which plays a key role in most cellular activities, is a reversible process mediated by protein kinases and phosphoprotein phosphatases. Protein kinases catalyse the transfer of the gamma phosphate from nucleotide triphosphates (often ATP) to one or more amino acid residues in a protein substrate side chain, resulting in a conformational change affecting protein function. Phosphoprotein phosphatases catalyse the reverse process. Protein kinases fall into three broad classes, characterised with respect to substrate specificity [PMID: 3291115]:

  • Serine/threonine-protein kinases
  • Tyrosine-protein kinases
  • Dual specificity protein kinases (e.g. MEK - phosphorylates both Thr and Tyr on target proteins)

Protein kinase function is evolutionarily conserved from Escherichia coli to human [PMID: 12471243]. Protein kinases play a role in a multitude of cellular processes, including division, proliferation, apoptosis, and differentiation [PMID: 12368087]. Phosphorylation usually results in a functional change of the target protein by changing enzyme activity, cellular location, or association with other proteins. The catalytic subunits of protein kinases are highly conserved, and several structures have been solved [PMID: 15078142], leading to large screens to develop kinase-specific inhibitors for the treatments of a number of diseases [PMID: 15320712].

This entry represents serine/threonine-protein kinases (EC: such as Unc-51 from Caenorhabditis elegans. Unc-51 is important for axonal elongation and axonal guidance [PMID: 16887826]. It is required for either the maintenance of axons (membrane turnover) or for an unknown neuronal function. C elegans worms lacking Unc-51 exhibit various abnormalities in axonal elongation and axonal structures. Unc-51 could also help control cell size along with Bec-1, as mutations in their corresponding genes results in a reduction in small body size without affecting cell number [PMID: 17890369].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.