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The effects of positively charged myristoylated peptides on eNOS phosphorylation are caveolae‐dependent.
Author(s) -
Krotova Karina,
Block Edward R.,
Zharikov Sergey
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a241-b
Subject(s) - myristoylation , enos , microbiology and biotechnology , chemistry , protein kinase b , cytoskeleton , phosphorylation , caveolae , actin cytoskeleton , stress fiber , biochemistry , biology , cell , enzyme , nitric oxide synthase
Recently we found that some myristoylated peptides were able to activate a number of enzymes in pulmonary artery endothelial cells (PAEC): eNOS, Akt, ERK 1/2, and MAPK p38. Screening a number of myristoylated peptides showed that all peptides containing a basic amino acid (AA) motif and more than 6 AA were able to activate eNOS in PAEC. We classified these active peptides as Myristoylated Cationic Peptides (MCP). We studied the mechanism of cell translocation of myr‐N‐ RLYRKRIWRSAGR –OH (mSc) as a representative of MCP. The process of translocation into the plasma membrane of PAEC was temperature‐independent but further internalization into the cell cytoplasm was temperature‐dependent. Disruption of caveolae in PAEC using methyl‐â‐cyclodextrin prevents cytoplasmic distribution of mSc and also abolishes the phosphorylation of eNOS and Akt but not ERK1/2 induced by mSc. Among 15 tested plasma membrane lipids mSc interacts with PIP3, PIP2 and phosphatidic acid. These biologically active lipids are important components controlling cellular processes such as proliferation, survival, and cytoskeletal rearrangement. We found that treatment of PAEC with mSc changed the cellular cytoskeleton, disassembling the actin stress fiber network and increasing cortical F‐actin. Our results suggest that interaction of MCP with plasma membrane lipids underlies the biological activity of MCP. This work was supported by the Florida DOH and NIH, NHLBI.