TIAM-1/GEF can shape somatosensory dendrites independently of its GEF activity by regulating F-actin localization

Leo Th Tang, Carlos A. Diaz-Balzac, Maisha Rahman, Nelson J. Ramirez-Suarez, Yehuda Salzberg, Maria I. Lázaro-Peña, Hannes E. Bülow

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


Dendritic arbors are crucial for nervous system assembly, but the intracellular mechanisms that govern their assembly remain incompletely understood. Here, we show that the dendrites of PVD neurons in Caenorhabditis elegans are patterned by distinct pathways downstream of the DMA-1 leucine-rich transmembrane (LRR-TM) receptor. DMA-1/LRR-TM interacts through a PDZ ligand motif with the guanine nucleotide exchange factor TIAM-1/GEF in a complex with act-4/Actin to pattern higher order 4° dendrite branches by localizing F-actin to the distal ends of developing dendrites. Surprisingly, TIAM-1/GEF appears to function independently of Rac1 guanine nucleotide exchange factor activity. A partially redundant pathway, dependent on HPO-30/Claudin, regulates formation of 2° and 3° branches, possibly by regulating membrane localization and trafficking of DMA-1/LRR-TM. Collectively, our experiments suggest that HPO-30/Claudin localizes the DMA-1/LRR-TM receptor on PVD dendrites, which in turn can control dendrite patterning by directly modulating F-actin dynamics through TIAM-1/GEF.

Original languageEnglish (US)
Article numbere38949
StatePublished - Jan 29 2019


  • C. elegans
  • GEF independent
  • PVD
  • actin
  • claudin
  • dendrites
  • developmental biology
  • guanine nucleotide exchange factor
  • neuroscience

ASJC Scopus subject areas

  • Neuroscience(all)
  • Immunology and Microbiology(all)
  • Biochemistry, Genetics and Molecular Biology(all)


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