Substrate recognition and transport mechanism of the PIN-FORMED auxin exporters

Trends Biochem Sci. 2023 Aug 11:S0968-0004(23)00172-X. doi: 10.1016/j.tibs.2023.07.006. Online ahead of print.ABSTRACTAuxins are pivotal plant hormones that regulate plant growth and transmembrane polar auxin transport (PAT) direct patterns of development. The PIN-FORMED (PIN) family of membrane transporters mediate auxin export from the plant cell and play crucial roles in PAT. Here we describe the recently solved structures of PIN transporters, PIN1, PIN3, and PIN8, and also their mechanisms of substrate recognition and transport of auxin. We compare structures of PINs in both inward- and outward-facing conformations, as well as PINs with different binding configurations for auxin. By this comparative analysis, a model emerges for an elevator transport mechanism. Central structural elements necessary for function are identified, and we show that these are shared with other distantly related protein families.PMID:37574372 | DOI:10.1016/j.tibs.2023.07.006

Source: Trends in Biochemical Sciences - August 13, 2023 Category: Biochemistry Authors: Kien Lam Ung Lukas Schulz David L Stokes Ulrich Z Hammes Bj ørn Panyella Pedersen Source Type: research