title: A draft of the human septin interactome.
abstract: BACKGROUND
  Septins belong to the GTPase superclass of proteins and have been functionally implicated in cytokinesis and the maintenance of cellular morphology. They are found in all eukaryotes, except in plants. In mammals, 14 septins have been described that can be divided into four groups. It has been shown that mammalian septins can engage in homo- and heterooligomeric assemblies, in the form of filaments, which have as a basic unit a hetero-trimeric core. In addition, it has been speculated that the septin filaments may serve as scaffolds for the recruitment of additional proteins.
  
  
  RESULTS
  Here, we performed yeast two-hybrid screens with human septins 1-10, which include representatives of all four septin groups. Among the interactors detected, we found predominantly other septins, confirming the tendency of septins to engage in the formation of homo- and heteropolymeric filaments.
  
  
  CONCLUSIONS
  If we take as reference the reported arrangement of the septins 2, 6 and 7 within the heterofilament, (7-6-2-2-6-7), we note that the majority of the observed interactions respect the "group rule", i.e. members of the same group (e.g. 6, 8, 10 and 11) can replace each other in the specific position along the heterofilament. Septins of the SEPT6 group preferentially interacted with septins of the SEPT2 group (p<0.001), SEPT3 group (p<0.001) and SEPT7 group (p<0.001). SEPT2 type septins preferentially interacted with septins of the SEPT6 group (p<0.001) aside from being the only septin group which interacted with members of its own group. Finally, septins of the SEPT3 group interacted preferentially with septins of the SEPT7 group (p<0.001). Furthermore, we found non-septin interactors which can be functionally attributed to a variety of different cellular activities, including: ubiquitin/sumoylation cycles, microtubular transport and motor activities, cell division and the cell cycle, cell motility, protein phosphorylation/signaling, endocytosis, and apoptosis.
authors.affiliation: Laboratório Nacional de Biociências, Centro Nacional de Pesquisa em Energia e Materiais, Campinas, Brasil.
authors.forename: Marcel
authors.initials: M
authors.lastname: Nakahira
authors.forename: Joci Neuby Alves
authors.initials: JN
authors.lastname: Macedo
authors.forename: Thiago Vargas
authors.initials: TV
authors.lastname: Seraphim
authors.forename: Nayara
authors.initials: N
authors.lastname: Cavalcante
authors.forename: Tatiana A C B
authors.initials: TA
authors.lastname: Souza
authors.forename: Julio Cesar Pissuti
authors.initials: JC
authors.lastname: Damalio
authors.forename: Luis Fernando
authors.initials: LF
authors.lastname: Reyes
authors.forename: Eliana M
authors.initials: EM
authors.lastname: Assmann
authors.forename: Marcos R
authors.initials: MR
authors.lastname: Alborghetti
authors.forename: Richard C
authors.initials: RC
authors.lastname: Garratt
authors.forename: Ana Paula U
authors.initials: AP
authors.lastname: Araujo
authors.forename: Nilson I T
authors.initials: NI
authors.lastname: Zanchin
authors.forename: João A R G
authors.initials: JA
authors.lastname: Barbosa
authors.forename: Jörg
authors.initials: J
authors.lastname: Kobarg
mesh_terms: D001667:Binding, Competitive; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D005810:Multigene Family; D011485:Protein Binding; D058112:Septins / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; C000602252:SEPTIN2 protein, human; C436485:SEPTIN6 protein, human; C113158:SEPTIN7 protein, human; D058112:Septins; C407343:septin 3