Switches.ELM

Switch #:

SWTI000318

Switch type:
Specificity

Switch subtype:
Motif hiding

Description:
Hiding of the NLS of MKL/myocardin-like protein 1 (Mkl1) by binding of G-actin to the RPEL motifs of MKL/myocardin-like protein 1 (Mkl1) prevents translocation of this transcription factor to the nucleus.

Participants:
(1) MKL/myocardin-like protein 1 (Mkl1)
(2) Actin, alpha skeletal muscle (Acta1)
(3) Importin subunit alpha-3 (Kpna3)

Interactions

Interaction #1 Mkl1 - Acta1

Is mutually exclusive with Interaction #2 Mkl1 - Kpna3

Interfaces
(1) LIG_Actin_RPEL_3 motif (₁₇LQLKLQQRRTREELVSQGIM₃₆ and ₆₁LKRKIRSRPERAELVRMHIL₈₀ and ₁₀₅LNEKIAQRPGPMELVEKNIL₁₂₄) in MKL/myocardin-like protein 1 (Mkl1)
(2) Actin_(4-377) in Actin, alpha skeletal muscle (Acta1)
Additional Information
Structural information: 2YJF

Interaction #2 Mkl1 - Kpna3

Is mutually exclusive with Interaction #1 Mkl1 - Acta1

Interfaces
(3) TRG_NLS_MonoExtN_4 motif (₆₂KRKIRS₆₇ and ₉₅KLKRARL₁₀₁) in MKL/myocardin-like protein 1 (Mkl1)
(4) Armadillo/beta-catenin-like repeat_(104-438) in Importin subunit alpha-3 (Kpna3)

Interaction Regulation
Effector binding Abrogation (Actin, alpha skeletal muscle (Acta1)) of the MKL/myocardin-like protein 1 (Mkl1) TRG_NLS_MonoExtN_4 motif - Importin subunit alpha-3 (Kpna3) Armadillo/beta-catenin-like repeat interaction

Additional Information
Structural information: 2YJF

Context

Switch localisation
Curated: cytosol
ELM curated: cytosol, Nuclear pore, nucleus, NLS-dependent protein nuclear import complex

Inferred: cytoplasm, nucleus

References

(1) An actin-regulated importin α/β-dependent extended bipartite NLS directs nuclear import of MRTF-A.
Pawłowski et al. EMBO J. (2010)

(2) Structure of a pentavalent G-actin*MRTF-A complex reveals how G-actin controls nucleocytoplasmic shuttling of a transcriptional coactivator.
Mouilleron et al. Sci Signal (2011)