GFP-FRNK disrupts focal adhesions and induces anoikis in neonatal rat ventricular myocytes

Maria C. Heidkamp, Allison L Bayer, Jared A. Kalina, Diane M. Eble, Allen M. Samarel

Research output: Contribution to journalArticle

109 Citations (Scopus)

Abstract

Focal adhesion kinase (FAK) is a nonreceptor protein tyrosine kinase involved in adhesion-dependent signal transduction. FAK is highly expressed in cultured neonatal rat ventricular myocytes (NRVMs) and undergoes tyrosine autophosphorylation in response to cell adhesion, stretch, and growth factor stimulation. We previously showed that inhibition of FAK phosphorylation by adenovirally mediated overexpression of FRNK (the autonomously expressed C-terminal domain of FAK) prevented endothelin-1 (ET)-induced NRVM hypertrophy. One question raised by these studies was whether FRNK localized to focal adhesions and displaced FAK from sites required for downstream signaling. Therefore, we constructed a replication-defective adenovirus encoding a GFP-FRNK fusion protein (Adv-GFP-FRNK) and examined its effects on NRVM cytoarchitecture and signaling. Uninfected NRVMs contained small amounts of endogenous FRNK. NRVMs infected with Adv-GFP-FRNK expressed much larger amounts of a 66-/68-kDa protein that localized to costameres and focal adhesions. GFP-FRNK overexpression suppressed basal and ET-induced FAK phosphorylation and also inhibited ET-induced phosphorylation of PYK2, the other member of the FAK family of nonreceptor protein tyrosine kinases. In contrast, GFP-FRNK overexpression did not prevent ET-induced ERK, JNK, or p70S6K phosphorylation. Furthermore, GFP-FRNK resulted in the loss of detectable FAK and paxillin in focal adhesions, which was accompanied by reduced levels of total paxillin and, ultimately, cell detachment and apoptosis. We conclude that FRNK functions as a dominant-negative inhibitor of adhesion-dependent signaling by displacing FAK from focal adhesions and interfering with the anchorage of NRVMs that is necessary for cell survival, a process known as anoikis.

Original languageEnglish
Pages (from-to)1282-1289
Number of pages8
JournalCirculation Research
Volume90
Issue number12
DOIs
StatePublished - Jun 28 2002
Externally publishedYes

Fingerprint

Anoikis
Focal Adhesion Protein-Tyrosine Kinases
Focal Adhesions
Muscle Cells
Endothelin-1
Phosphorylation
Paxillin
Protein-Tyrosine Kinases
Costameres
70-kDa Ribosomal Protein S6 Kinases
Adenoviridae
Hypertrophy
Tyrosine
Signal Transduction
Cell Survival
Intercellular Signaling Peptides and Proteins
Proteins
Apoptosis

Keywords

  • Adenovirus
  • Apoptosis
  • Focal adhesion kinase
  • Paxillin
  • PYK2

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine

Cite this

GFP-FRNK disrupts focal adhesions and induces anoikis in neonatal rat ventricular myocytes. / Heidkamp, Maria C.; Bayer, Allison L; Kalina, Jared A.; Eble, Diane M.; Samarel, Allen M.

In: Circulation Research, Vol. 90, No. 12, 28.06.2002, p. 1282-1289.

Research output: Contribution to journalArticle

Heidkamp, Maria C. ; Bayer, Allison L ; Kalina, Jared A. ; Eble, Diane M. ; Samarel, Allen M. / GFP-FRNK disrupts focal adhesions and induces anoikis in neonatal rat ventricular myocytes. In: Circulation Research. 2002 ; Vol. 90, No. 12. pp. 1282-1289.
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AU - Bayer, Allison L

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AU - Samarel, Allen M.

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