TY - JOUR

T1 - Two Transient Receptor Potential Channels at Focal Adhesions

AU - Mitsou, Ioli

AU - Carlson, Cathrine Rein

AU - Multhaupt, Hinke A.B.

AU - Brakebusch, Cord

AU - Couchman, John R.

N1 - Publisher Copyright: © The Author(s) 2023.

PY - 2023

Y1 - 2023

N2 - Recently there have been reports that identify two transient receptor potential channels in cell–matrix junctions known as focal adhesions. These are the calcium channel TRP canonical 7 and the calcium-activated monovalent ion channel, TRP melastatin (TRPM) 4. Here, we report on the occurrence of TRPM4 in focal adhesions of fibroblasts. Of three commercial antibodies recognizing this channel, only one yielded focal adhesion staining, while the other two did not. The epitope recognized by the focal adhesion-localizing antibody was mapped to the extreme C-terminus of the TRPM4 protein. The other two antibodies bind to N-terminal regions of the TRPM4 proteins. Deletion of the TRPM4 gene by CRISPR/cas9 techniques confirmed that this channel is a bona fide focal adhesion component, while expression of full-length TRPM4 proteins suggested that processing may occur to yield a form that localizes to focal adhesions. Given the reports that this channel may influence migratory behavior of cells and is linked to cardiovascular disease, TRPM4 functions in adhesion should be explored in greater depth. (J Histochem Cytochem 71: 495–508, 2023).

AB - Recently there have been reports that identify two transient receptor potential channels in cell–matrix junctions known as focal adhesions. These are the calcium channel TRP canonical 7 and the calcium-activated monovalent ion channel, TRP melastatin (TRPM) 4. Here, we report on the occurrence of TRPM4 in focal adhesions of fibroblasts. Of three commercial antibodies recognizing this channel, only one yielded focal adhesion staining, while the other two did not. The epitope recognized by the focal adhesion-localizing antibody was mapped to the extreme C-terminus of the TRPM4 protein. The other two antibodies bind to N-terminal regions of the TRPM4 proteins. Deletion of the TRPM4 gene by CRISPR/cas9 techniques confirmed that this channel is a bona fide focal adhesion component, while expression of full-length TRPM4 proteins suggested that processing may occur to yield a form that localizes to focal adhesions. Given the reports that this channel may influence migratory behavior of cells and is linked to cardiovascular disease, TRPM4 functions in adhesion should be explored in greater depth. (J Histochem Cytochem 71: 495–508, 2023).

KW - cell-matrix adhesion

KW - cytoskeleton

KW - epitope mapping

KW - ion channel

KW - junctions

U2 - 10.1369/00221554231194119

DO - 10.1369/00221554231194119

M3 - Journal article

C2 - 37596792

AN - SCOPUS:85169848627

VL - 71

SP - 495

EP - 508

JO - Journal of Histochemistry and Cytochemistry

JF - Journal of Histochemistry and Cytochemistry

SN - 0022-1554

IS - 9

ER -