An evolutionarily conserved motif is required for Plasmodesmata-located protein 5 to regulate cell-to-cell movement

Area of Science:

• Plant molecular biology
• Cell biology
• Membrane protein function

Background:

• Cell surface receptors and receptor-like proteins (RLPs) use transmembrane domains (TMDs) for regulation.
• Plant RLPs, like Arabidopsis thaliana Plasmodesmata-located protein 5 (PDLP5), localize to plasmodesmata, regulating intercellular transport.

Purpose of the Study:

• Investigate the role of the PDLP5 TMD in its function.
• Determine if the TMD is essential for plasmodesmal targeting and PDLP5 activity.

Main Methods:

• Computational modeling to analyze PDLP TMD dimerization propensities.
• Functional analysis of PDLP5 and its TMD in regulating cell-to-cell movement.

Main Results:

• The PDLP5 TMD is essential for function but not plasmodesmal targeting.
• The TMD mediates PDLP5 self-interaction and contains a conserved motif critical for regulating cell-to-cell movement.
• Computational models indicate a high propensity for PDLP TMD dimerization.

Conclusions:

• The PDLP5 TMD plays vital roles beyond membrane anchoring, including mediating self-interaction and regulating intercellular transport.
• TMD dimerization may be a conserved mechanism for PDLP family members to control cell-to-cell communication.