The regulation of localization of FAK and Pyk2 to focal adhesions can be independently influenced by the presence or absence of specific binding partners, for example, gelsolin has been reported to bind Pyk2 but not FAK [40] as well as differences in the affinity of FAK and Pyk2 for shared binding partners within the focal adhesions, such as paxillin [41] [43].
In these studies, high-affinity binding partners, for example biotin − (strept avadin and/or digoxin − anti-digoxin antibodies were used.
The same principle of methodology could be very useful in addressing proteomic questions, such as rapid screening of the maize proteome for binding partners, for example proteins involved in hormone regulation or defence.
One future avenue of research will be the identification of putative binding partners, for example by bioinformatic analysis, searching for genes with similar phylogenetic profiles as those of the inserted domains.
Faster association has been attributed to increased electrostatic attraction between the binding partners, for example, for binding between TEM1 beta-lactamase and its protein inhibitor BLIP [ 53], but it can also originate from mutations of noninterfacial residues as in study [ 54].
For example, mutations in eIF2B, a binding partner for eIF2α in translation initiation, cause leukoencephalopathy with VWM, a childhood onset autosomal recessive neurodegenerative disorder (8, 9).
Moreover, Smad1/Mad is a direct binding partner for YAP/Yki in both Drosophila and humans [11, 36].
Although no definitive binding partner for Plxdc2 has been identified, several studies have isolated nidogen as a binding partner for the related protein, Plxdc1 [43], [43].
Basigin is the preferred binding partner for MCT1, MCT3 and MCT4, and embigin for MCT2.
When their interactions with other proteins have been dissected, the different PDZ domains of a single protein often have been found to have distinct binding partners (see for example the Uniprot entry for MPDZ [ 13]).
