TY - JOUR
T1 - Proteins involved in sleep homeostasis
T2 - Biophysical characterization of INC and its partners
AU - Pirone, Luciano
AU - Smaldone, Giovanni
AU - Esposito, Carla Lucia
AU - Balasco, Nicole
AU - Petoukhov, Maxim V.
AU - Spilotros, Alessandro
AU - Svergun, Dmitri I.
AU - Di Gaetano, Sonia
AU - Vitagliano, Luigi
AU - Pedone, Emilia Maria
PY - 2016/12/1
Y1 - 2016/12/1
N2 - The insomniac protein of Drosophila melanogaster (INC) has a crucial role in sleep homeostasis as flies lacking the inc gene exhibit strikingly reduced and poorly consolidated sleep. Nevertheless, in vitro characterizations of INC biophysical properties and partnerships have not been yet reported. Here we report the heterologous expression of the protein and its characterization using a number of different techniques. Present data indicate that INC is endowed with a remarkable stability, which results from the cooperation of the two protein domains. Moreover, we also demonstrated and quantified the ability of INC to recognize its potential partners Cul3 and dGRASP. Taking into account the molecular organization of the protein, these two partners may be anchored simultaneously. Although there is no evident relationship between the reported INC functions and dGRASP binding, our data suggest that INC may cooperate as ligase adaptor to dGRASP ubiquitination. SAXS data collected on the complex between INC and Cul3, which represent the first structural characterization of this type of assemblies, clearly highlight the highly dynamic nature of these complexes. This strongly suggests that the functional behavior of these proteins cannot be understood if dynamic effects are not considered. Finally, the strict analogy of the biochemical/biophysical properties of INC and of its human homolog KCTD5 may reliably indicate that this latter protein and/or the closely related proteins KCTD2/KCTD17 may play important roles in human sleep regulation.
AB - The insomniac protein of Drosophila melanogaster (INC) has a crucial role in sleep homeostasis as flies lacking the inc gene exhibit strikingly reduced and poorly consolidated sleep. Nevertheless, in vitro characterizations of INC biophysical properties and partnerships have not been yet reported. Here we report the heterologous expression of the protein and its characterization using a number of different techniques. Present data indicate that INC is endowed with a remarkable stability, which results from the cooperation of the two protein domains. Moreover, we also demonstrated and quantified the ability of INC to recognize its potential partners Cul3 and dGRASP. Taking into account the molecular organization of the protein, these two partners may be anchored simultaneously. Although there is no evident relationship between the reported INC functions and dGRASP binding, our data suggest that INC may cooperate as ligase adaptor to dGRASP ubiquitination. SAXS data collected on the complex between INC and Cul3, which represent the first structural characterization of this type of assemblies, clearly highlight the highly dynamic nature of these complexes. This strongly suggests that the functional behavior of these proteins cannot be understood if dynamic effects are not considered. Finally, the strict analogy of the biochemical/biophysical properties of INC and of its human homolog KCTD5 may reliably indicate that this latter protein and/or the closely related proteins KCTD2/KCTD17 may play important roles in human sleep regulation.
KW - Binding
KW - Homologs
KW - Protein stability
KW - Protein-protein interactions
KW - Solution scattering
UR - http://www.scopus.com/inward/record.url?scp=84989299843&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84989299843&partnerID=8YFLogxK
U2 - 10.1016/j.biochi.2016.09.013
DO - 10.1016/j.biochi.2016.09.013
M3 - Article
AN - SCOPUS:84989299843
VL - 131
SP - 106
EP - 114
JO - Biochimie
JF - Biochimie
SN - 0300-9084
ER -