Interaction specificity of Arabidopsis 14-3-3 proteins with phototropin receptor kinases

Phototropin receptor kinases play an important role in optimising plant growth in response to blue light. Much is known regarding their photochemical reactivity, yet little progress has been made to identify downstream signalling components. Here, we isolated several interacting proteins for Arabidopsis phototropin 1 (phot1) by yeast two-hybrid screening. These include members of the NPH3/RPT2 (NRL) protein family, proteins associated with vesicle trafficking, and the 14-3-3 lambda (λ) isoform from Arabidopsis. 14-3-3λ and phot1 were found to colocalise and interact in vivo. Moreover, 14-3-3 binding to phot1 was limited to non-epsilon 14-3-3 isoforms and was dependent on key sites of receptor autophosphorylation. No 14-3-3 binding was detected for Arabidopsis phot2, suggesting that 14-3-3 proteins are specific to phot1 signalling.Structured summaryMINT-7146953: PHOT1 (uniprotkb:O48963) physically interacts (MI:0915) with ARF7 (uniprotkb:Q9LFJ7) by two hybrid (MI:0018)MINT-7147335: PHOT1 (uniprotkb:O48963) physically interacts (MI:0914) with 14-3-3 phi (uniprotkb:P46077) by far Western blotting (MI:0047)MINT-7146854: PHOT1 (uniprotkb:O48963) physically interacts (MI:0915) with RPT2 (uniprotkb:Q682S0) by two hybrid (MI:0018)MINT-7147215: PHOT1 (uniprotkb:O48963) physically interacts (MI:0914) with 14-3-3 lambda (uniprotkb:P48349) by anti tag coimmunoprecipitation (MI:0007)MINT-7147044, MINT-7147185, MINT-7147200, MINT-7147413: PHOT1 (uniprotkb:O48963) physically interacts (MI:0914) with 14-3-3 lambda (uniprotkb:P48349) by far Western blotting (MI:0047)MINT-7146983: PHOT1 (uniprotkb:O48963) physically interacts (MI:0915) with 14-3-3 lambda (uniprotkb:P48349) by two hybrid (MI:0018)MINT-7146871: PHOT1 (uniprotkb:O48963) physically interacts (MI:0915) with NPH3-like (uniprotkb:Q9S9Q9) by two hybrid (MI:0018)MINT-7146905: PHOT1 (uniprotkb:O48963) physically interacts (MI:0915) with ARF2 (uniprotkb:Q9M1P5) by two hybrid (MI:0018)MINT-7147364: PHOT1 (uniprotkb:O48963) physically interacts (MI:0914) with 14-3-3 upsilon (uniprotkb:P42645) by far Western blotting (MI:0047)MINT-7147234: PHOT1 (uniprotkb:O48963) physically interacts (MI:0914) with 14-3-3 kappa (uniprotkb:P48348) by far Western blotting (MI:0047)