PROSITE documentation PDOC51757
Class I myosin tail homology (TH1) domain profile


Class I myosins (Myo1s) are widely expressed in eukaryotic cells. Myo1s exist as monomers and can sense cellular mechanical forces and function as tension-sensitive anchors or transporters. Each Myo1 contains from N terminus to C terminus, a motor domain (see <PDOC51456>), a neck region consisting of several calmodulin (CaM)-binding IQ motifs (see <PDOC50096>) and a tail region. All Myo1s contain a tail homology (TH1) domain featuring an embedded pleckstrin-homology (PH) domain (see <PDOC50003>) capable of binding to lipid membranes. In addition, Myo1s with long tails also contain a TH2 (or GPA) domain and a C-terminal TH3 (or SH3) domain (see <PDOC50002>), the latter of which may be responsible for binding to cargos. All Myo1s are capable of bridging actin cytoskeletons with lipid membranes by using their motor heads and tail TH1 domains. The TH1 domain is an extended PH domain capable of binding to lipids [1,2].

The TH1 domain forms an extended PH domain, with its N and C termini capped by two α-helices and five β-strands, respectively (see <PDB:4R8G>). The center of TH1 contains a canonical PH domain fold formed by a seven-stranded β-barrel and an α-helix.

The profile we developed covers the entire TH1 domain.

Last update:

May 2015 / First entry.


Technical section

PROSITE method (with tools and information) covered by this documentation:

TH1, PS51757; Class I myosin tail homology (TH1) domain profile  (MATRIX)


1AuthorsLu Q. Li J. Ye F. Zhang M.
TitleStructure of myosin-1c tail bound to calmodulin provides insights into calcium-mediated conformational coupling.
SourceNat. Struct. Mol. Biol. 22:81-88(2015).
PubMed ID25437912

2AuthorsPatino-Lopez G. Aravind L. Dong X. Kruhlak M.J. Ostap E.M. Shaw S.
TitleMyosin 1G is an abundant class I myosin in lymphocytes whose localization at the plasma membrane depends on its ancient divergent pleckstrin homology (PH) domain (Myo1PH).
SourceJ. Biol. Chem. 285:8675-8686(2010).
PubMed ID20071333

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