Related Experiment Video
Updated: Jul 20, 2026

PIP-on-a-chip: A Label-free Study of Protein-phosphoinositide Interactions
Published on: July 27, 2017
Myo1c binds phosphoinositides through a putative pleckstrin homology domain
David E Hokanson1, Joseph M Laakso, Tianming Lin
1The Pennsylvania Muscle Institute and Department of Physiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6085, USA.
Abstract:
Myo1c is a member of the myosin superfamily that binds phosphatidylinositol-4,5-bisphosphate (PIP(2)), links the actin cytoskeleton to cellular membranes and plays roles in mechano-signal transduction and membrane trafficking. We located and characterized two distinct membrane binding sites within the regulatory and tail domains of this myosin. By sequence, secondary structure, and ab initio computational analyses, we identified a phosphoinositide binding site in the tail to be a putative pleckstrin homology (PH) domain. Point mutations of residues known to be essential for polyphosphoinositide binding in previously characterized PH domains inhibit myo1c binding to PIP(2) in vitro, disrupt in vivo membrane binding, and disrupt cellular localization. The extended sequence of this binding site is conserved within other myosin-I isoforms, suggesting they contain this putative PH domain. We also characterized a previously identified membrane binding site within the IQ motifs in the regulatory domain. This region is not phosphoinositide specific, but it binds anionic phospholipids in a calcium-dependent manner. However, this site is not essential for in vivo membrane binding.
More Related Videos
08:07Identification of Inositol Phosphate or Phosphoinositide Interacting Proteins by Affinity Chromatography Coupled to Western Blot or Mass Spectrometry
Published on: July 26, 2019
07:26Single-molecule Super-resolution Imaging of Phosphatidylinositol 4,5-bisphosphate in the Plasma Membrane with Novel Fluorescent Probes
Published on: October 15, 2016
Related Concept Videos
Phosphoinositides and PIPs
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...
Overview of Myosin Structure and Function
IP3/DAG Signaling Pathway
Mechanism of Filopodia Formation
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Role of Myosin in Cell Migration
Myosin II is a hexamer comprising two heavy chains with globular heads and coiled-coil tails, two regulatory light chains, and two essential light chains. The ATPase sites on the myosin heads hydrolyze ATP, and the released phosphate generates the force for contraction. It is...
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...