title: Nucleotide-binding mechanisms in pseudokinases.
abstract: Pseudokinases are classified by the lack of one or several of the highly conserved motifs involved in nucleotide (nt) binding or catalytic activity of protein kinases (PKs). Pseudokinases represent ∼10% of the human kinome and they are found in all evolutionary classes of kinases. It has become evident that pseudokinases, which were initially considered somewhat peculiar dead kinases, are important components in several signalling cascades. Furthermore, several pseudokinases have been linked to human diseases, particularly cancer, which is raising interest for therapeutic approaches towards these proteins. The ATP-binding pocket is a well-established drug target and elucidation of the mechanism and properties of nt binding in pseudokinases is of significant interest and importance. Recent studies have demonstrated that members of the pseudokinase family are very diverse in structure as well as in their ability and mechanism to bind nts or perform phosphoryl transfer reactions. This diversity also precludes prediction of pseudokinase function, or the importance of nt binding for said function, based on primary sequence alone. Currently available data indicate that ∼40% of pseudokinases are able to bind nts, whereas only few are able to catalyse occasional phosphoryl transfer. Pseudokinases employ diverse mechanisms to bind nts, which usually occurs at low, but physiological, affinity. ATP binding serves often a structural role but in most cases the functional roles are not precisely known. In the present review, we discuss the various mechanisms that pseudokinases employ for nt binding and how this often low-affinity binding can be accurately analysed.
authors.affiliation: School of Medicine, University of Tampere, Biokatu 8, FI-33014 Tampere, Finland henrik.hammaren@uta.fi olli.silvennoinen@uta.fi.
authors.forename: Henrik M
authors.initials: HM
authors.lastname: Hammarén
authors.affiliation: School of Medicine, University of Tampere, Biokatu 8, FI-33014 Tampere, Finland.
authors.forename: Anniina T
authors.initials: AT
authors.lastname: Virtanen
authors.affiliation: School of Medicine, University of Tampere, Biokatu 8, FI-33014 Tampere, Finland Clinical Hematology, Department of Internal Medicine, Tampere University Hospital, Medisiinarinkatu 3, FI-33520 Tampere, Finland henrik.hammaren@uta.fi olli.silvennoinen@uta.fi.
authors.forename: Olli
authors.initials: O
authors.lastname: Silvennoinen
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry* / Q000235:genetics; D020816:Amino Acid Motifs; D000818:Animals; D001665:Binding Sites; D006801:Humans; D010770:Phosphotransferases / Q000737:chemistry* / Q000235:genetics; D017434:Protein Structure, Tertiary
chemical_list: D000255:Adenosine Triphosphate; D010770:Phosphotransferases
keywords: ATP; kinase activity; kinome; nucleotide binding; pseudokinase; signalling