Switch #: SWTI000713

Switch type: Pre-assembly

Switch subtype: Composite binding site formation

Description:
Binding of Auxin-responsive protein IAA17 (IAA17) to Protein TRANSPORT INHIBITOR RESPONSE 1 (TIR1), an F-box substrate recognition subunit of the SCF E3 ubiquitin ligase, depends on binding of the plant hormone auxin to TIR1, as this pre-assembled complex provides a composite binding site for the degron motif in IAA17. Subsequent ubiquitylation of IAA17 by the SCF targets this transcriptional repressor for proteasomal degradation, a pre-requisite for the transcriptional response to auxin.

Participants:
(1) auxin
(2) Protein TRANSPORT INHIBITOR RESPONSE 1 (TIR1)
(3) Auxin-responsive protein IAA17 (IAA17)

This is a sequential switch. The interactions in this switch take place in a defined order. The order is defined by numbers to the left of each interaction. More than one interaction can occur in each step, these interactions occur independently but are necessary for future step

1Interaction #1 IAA17 - TIR1

Interfaces
(1) auxin in auxin
(2) Protein TRANSPORT INHIBITOR RESPONSE 1 (TIR1)

2Interaction #2 IAA17 - Interaction #1 - - TIR1

Requires Interaction #1 - - TIR1

Interfaces
(3) DEG_SCF_TIR1_1 motif (₈₂QVVGWPPVRSYR₉₃) in Auxin-responsive protein IAA17 (IAA17)
(4) Interaction #1 - - TIR1

(1) Auxin regulates SCF(TIR1)-dependent degradation of AUX/IAA proteins.
Gray et al. Nature (2001)