Flightless-I, a gelsolin family member and transcriptional regulator, preferentially binds directly to activated cytosolic CaMK-II

Seward, Matthew E.; Easley, Charles A.; McLeod, Jamie J.; Myers, Alexandra L.; Tombes, Robert M.

doi:10.1016/j.febslet.2008.06.037

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Volume 582, Issue 17 , Pages 2489-2495, 23 July 2008

Flightless-I, a gelsolin family member and transcriptional regulator, preferentially binds directly to activated cytosolic CaMK-II

Edited by Jesus Avila

Matthew E. Seward
- Department of Biology, Virginia Commonwealth University, 1000 West Cary Street, Richmond, VA 23284-2012, United States
- Current address: Department of Cell Biology, University of Virginia, Charlottesville, VA 22908, United States.
Charles A. Easley IV
- Department of Biochemistry, Virginia Commonwealth University, 1101 East Marshall Street, Richmond, VA 23298-0614, United States
- Current address: Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA 15213, United States.
Jamie J. McLeod
- Department of Biology, Virginia Commonwealth University, 1000 West Cary Street, Richmond, VA 23284-2012, United States
Alexandra L. Myers
- Department of Biology, Virginia Commonwealth University, 1000 West Cary Street, Richmond, VA 23284-2012, United States
Robert M. Tombes
- Department of Biology, Virginia Commonwealth University, 1000 West Cary Street, Richmond, VA 23284-2012, United States
- Department of Biochemistry, Virginia Commonwealth University, 1101 East Marshall Street, Richmond, VA 23298-0614, United States
- Massey Cancer Center, Virginia Commonwealth University, 401 College Street, Richmond, Virginia 23298-0037, United States
- Corresponding author. Address: Department of Biology, Virginia Commonwealth University, 1000 West Cary Street, Richmond, VA 23284-2012, United States. Fax: +1 804 828 0503.

Received 29 April 2008; received in revised form 29 May 2008; accepted 5 June 2008. published online 26 June 2008.

Abstract

In order to evaluate links between Ca²⁺/calmodulin (CaM)-dependent protein kinase type II (CaMK-II) and cell cycle progression, CaMK-II binding partners were sought in proliferating cells by epitope-tag tandem mass spectrometry. One protein identified was the gelsolin family member, flightless-I (Fli-I). Fli-I is not a CaMK-II substrate, but binds directly and preferentially to constitutively active (T²⁸⁷D) CaMK-II over inactive CaMK-II. Fli-I gradually enters the nucleus upon CaMK-II inhibition and is retained in the cytosol by T²⁸⁷D CaMK-II. CaMK-II inhibition and Fli-I overexpression suppress transcription of β-catenin dependent transcriptional reporters, whereas Fli-I suppression enhances their transcription. These findings support a novel mechanism whereby cytosolic CaMK-II influences β-catenin dependent gene expression through Fli-I.

Structured summary

MINT-6603828:

delta CaMK-II (uniprotkb:Q6PHZ2) binds (MI:0407) to Flightless-I (uniprotkb:Q9JJ28) by anti bait coimmunoprecipitation (MI:0006)

MINT-6603847:

delta CaMK-II (uniprotkb:Q6PHZ2) phosphorylates (MI:0217) MAP2 (uniprotkb:P20357) by protein kinase assay (MI:0424)

MINT-6603768:

beta CaMK-II (uniprotkb:P28652) physically interacts (MI:0218) with Flightless-I (uniprotkb:Q9JJ28) by anti bait coimmunoprecipitation (MI:0006)

MINT-6603759, MINT-6603776, MINT-6603786:

delta CaMK-II (uniprotkb:Q6PHZ2) physically interacts (MI:0218) with Flightless-I (uniprotkb:Q9JJ28) by anti bait coimmunoprecipitation (MI:0006)

MINT-6603724:

CaMK-II delta (uniprotkb:Q6PHZ2) physically interacts (MI:0218) with beta 5tubulin (uniprotkb:P99024), beta 2c tubulin (uniprotkb:P68372), alpha 1a tubulin (uniprotkb:P68369), b-Actin (uniprotkb:P60710), Tropomodulin-3 (uniprotkb:Q9JHJ0), Flightless-I (uniprotkb:Q9JJ28), FLAP1 (uniprotkb:Q3UZ39) and FLAP2 (uniprotkb:Q91WK0) by anti tag coimmunoprecipitation (MI:0007).

Abbreviations: CaMK-II, Ca²⁺/CaM-dependent protein kinase type II, CaM, calmodulin, Fli-I, flightless-I, Tcf/Lef, T-cell factor/lymphoid-enhancer binding factor-1, GFP, green fluorescent protein, AIP, auto-inhibitory peptide