Acanthameba Myosins

Korn, E D.

Abstract

The essential elements for substrate specificity for myosin I heavy chain kinase has been studied with the use of synthetic peptides as substrates. One basic amino acid has been found essential, and two preferable, on the N-terminal side of the phosphorylation site and a tyrosine reside is required 2 positions away on the C-terminal side. The activity of the kinase is about 50-fold enhanced by autophosphorylation of up to 8 sites and this autophosphorylation is about 20-fold stimulated by the presence of acidic phospholipids. Previous fluorescence immunolocalization studies of myosin I have been extended by immunoelectron microscopy. Myosin I has been found to be located at the plasma membrane, as previously inferred, and also at the membrane of the contractile vacuole, a new observation.

Funding Agency

• Agency: National Institute of Health (NIH)
• Institute: National Heart, Lung, and Blood Institute (NHLBI)
• Type: Intramural Research (Z01)
• Project #: 1Z01HL000506-15
• Application #: 3878891
• Support Year: 15
• Fiscal Year: 1990

Institution

• Name: National Heart, Lung, and Blood Institute
• Country: United States

Publications

Baek, Kyuwon; Liu, Xiong; Ferron, Francois et al. (2008) Modulation of actin structure and function by phosphorylation of Tyr-53 and profilin binding. Proc Natl Acad Sci U S A 105:11748-53

Hwang, Kae-Jung; Mahmoodian, Fatemeh; Ferretti, James A et al. (2007) Intramolecular interaction in the tail of Acanthamoeba myosin IC between the SH3 domain and a putative pleckstrin homology domain. Proc Natl Acad Sci U S A 104:784-9

Szczepanowska, Joanna; Korn, Edward D; Brzeska, Hanna (2006) Activation of myosin in HeLa cells causes redistribution of focal adhesions and F-actin from cell center to cell periphery. Cell Motil Cytoskeleton 63:356-74

Liu, Xiong; Shu, Shi; Hong, Myoung-Soon S et al. (2006) Phosphorylation of actin Tyr-53 inhibits filament nucleation and elongation and destabilizes filaments. Proc Natl Acad Sci U S A 103:13694-9

Shu, Shi; Mahadeo, Dana C; Liu, Xiong et al. (2006) S-adenosylhomocysteine hydrolase is localized at the front of chemotaxing cells, suggesting a role for transmethylation during migration. Proc Natl Acad Sci U S A 103:19788-93

Shu, Shi; Liu, Xiong; Korn, Edward D (2005) Blebbistatin and blebbistatin-inactivated myosin II inhibit myosin II-independent processes in Dictyostelium. Proc Natl Acad Sci U S A 102:1472-7

Liu, Xiong; Shu, Shi; Kovacs, Mihaly et al. (2005) Biological, biochemical, and kinetic effects of mutations of the cardiomyopathy loop of Dictyostelium myosin II: importance of ALA400. J Biol Chem 280:26974-83

Ishikawa, Takashi; Cheng, Naiqian; Liu, Xiong et al. (2004) Subdomain organization of the Acanthamoeba myosin IC tail from cryo-electron microscopy. Proc Natl Acad Sci U S A 101:12189-94

Korn, Edward D (2004) The discovery of unconventional myosins: serendipity or luck? J Biol Chem 279:8517-25

Brzeska, Hanna; Szczepanowska, Joanna; Matsumura, Fumio et al. (2004) Rac-induced increase of phosphorylation of myosin regulatory light chain in HeLa cells. Cell Motil Cytoskeleton 58:186-99