RT Journal Article
SR Electronic
T1 Sequence features of MADS-domain proteins that act as hubs in the protein-protein interaction network controlling flower development
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 125294
DO 10.1101/125294
A1 Florian Rümplera
A1 Günter Theißen
A1 Rainer Melzer
YR 2017
UL http://biorxiv.org/content/early/2017/04/07/125294.abstract
AB Protein-protein interaction networks (PPIs) are usually scale-free networks that contain a small number of highly connected nodes (hubs) and many poorly connected nodes. However, the molecular mechanisms that underlie the promiscuous interactions of hub proteins remain largely unknown. Here, we show that the floral homeotic MADS-domain transcription factor SEPALLATA3 from Arabidopsis thaliana can act as a hub in the PPI controlling flower development because it contains leucine residues at inter- and intramolecular interaction interfaces. Comprehensive sequence analyses of diverse MADS-domain proteins indicate exceedingly high conservation of the identified leucine residues within SEPALLATA-subfamily proteins, whereas non-hub MADS-domain proteins exhibit preferences for other amino acids at homologous sites. Our results indicate that the conservation of leucine residues at positions critical for protein-protein interactions contributed significantly to the present-day structure of the PPI and may have facilitated the evolution of the flower.