title: Orphan G protein-coupled receptor GPRC5A modulates integrin β1-mediated epithelial cell adhesion.
abstract: G-Protein Coupled Receptor (GPCR), Class C, Group 5, Member A (GPRC5A) has been implicated in several malignancies. The underlying mechanisms, however, remain poorly understood. Using a panel of human cell lines, we demonstrate that CRISPR/Cas9-mediated knockout and RNAi-mediated depletion of GPRC5A impairs cell adhesion to integrin substrates: collagens I and IV, fibronectin, as well as to extracellular matrix proteins derived from the Engelbreth-Holm-Swarm (EHS) mouse sarcoma (Matrigel). Consistent with the phenotype, knock-out of GPRC5A correlated with a reduced integrin β1 (ITGB1) protein expression, impaired phosphorylation of the focal adhesion kinase (FAK), and lower activity of small GTPases RhoA and Rac1. Furthermore, we provide the first evidence for a direct interaction between GPRC5A and a receptor tyrosine kinase EphA2, an upstream regulator of FAK, although its contribution to the observed adhesion phenotype is unclear. Our findings reveal an unprecedented role for GPRC5A in regulation of the ITGB1-mediated cell adhesion and it's downstream signaling, thus indicating a potential novel role for GPRC5A in human epithelial cancers.
authors.affiliation: a Institute for Molecular Medicine Finland (FIMM), University of Helsinki , Helsinki , Finland.
authors.forename: Daria R
authors.identifier: http://orcid.org/0000-0002-5038-1724
authors.initials: DR
authors.lastname: Bulanova
authors.affiliation: a Institute for Molecular Medicine Finland (FIMM), University of Helsinki , Helsinki , Finland.
authors.forename: Yevhen A
authors.initials: YA
authors.lastname: Akimov
authors.affiliation: c Turku Centre for Biotechnology , University of Turku and Abo Academy , Turku , Finland.
authors.forename: Anne
authors.initials: A
authors.lastname: Rokka
authors.affiliation: a Institute for Molecular Medicine Finland (FIMM), University of Helsinki , Helsinki , Finland.|b Department of Mathematics and Statistics , University of Turku , Turku , Finland.
authors.forename: Teemu D
authors.initials: TD
authors.lastname: Laajala
authors.affiliation: a Institute for Molecular Medicine Finland (FIMM), University of Helsinki , Helsinki , Finland.|b Department of Mathematics and Statistics , University of Turku , Turku , Finland.
authors.forename: Tero
authors.initials: T
authors.lastname: Aittokallio
authors.affiliation: c Turku Centre for Biotechnology , University of Turku and Abo Academy , Turku , Finland.
authors.forename: Petri
authors.identifier: http://orcid.org/0000-0001-9204-039X
authors.initials: P
authors.lastname: Kouvonen
authors.affiliation: a Institute for Molecular Medicine Finland (FIMM), University of Helsinki , Helsinki , Finland.
authors.forename: Teijo
authors.initials: T
authors.lastname: Pellinen
authors.affiliation: a Institute for Molecular Medicine Finland (FIMM), University of Helsinki , Helsinki , Finland.
authors.forename: Sergey G
authors.initials: SG
authors.lastname: Kuznetsov
mesh_terms: D064113:CRISPR-Cas Systems / Q000235:genetics / Q000502:physiology; D002448:Cell Adhesion / Q000235:genetics / Q000502:physiology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics / Q000502:physiology; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D019012:Integrin beta1 / Q000235:genetics / Q000378:metabolism*; D061986:MCF-7 Cells; D034622:RNA Interference; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D053719:Tandem Mass Spectrometry
chemical_list: C116760:GPRC5A protein, human; D019012:Integrin beta1; D043562:Receptors, G-Protein-Coupled
keywords: ECM; EphA2; GPRC5A; integrin β1; matrix adhesion