linkprotein1

Linkprotein1 (linkprotein1), abbreviated LP1, is a eukaryotic adaptor protein that connects activated cell-surface receptors to the actin cytoskeleton. It was identified in screens for proteins associated with receptor tyrosine kinases and is conserved across vertebrates and many invertebrates.

LP1 is about 320 amino acids long and features a central coiled-coil domain and an N-terminal motif that binds phosphotyrosine-containing sequences. In cells, LP1 localizes to the cytoskeleton, with enrichment at the cortex and at focal adhesions during migration.

Functionally, LP1 acts as a scaffold that recruits actin-regulatory factors to activated receptors, promoting remodeling of the actin network and turnover of adhesion sites. It directly binds actin and interacts with focal-adhesion proteins such as talin and vinculin and with components of the ARP2/3 complex, linking signaling to cytoskeletal dynamics.

LP1 expression is broad, with higher levels in tissues undergoing remodeling; phosphorylation by kinases including CK2 modulates its interactions. In model systems, altered LP1 levels affect cell migration and adhesion, and some studies report changes in signaling downstream of receptor tyrosine kinases.

Researchers use antibodies against LP1 and overexpression or knockout constructs to study its role in cells.