TY - JOUR
T1 - Structural and energetic basis of ALS-causing mutations in the atypical proline-tyrosine nuclear localization signal of the Fused in Sarcoma protein (FUS)
AU - Zhang, Zi Chao
AU - Chook, Yuh Min
PY - 2012/7/24
Y1 - 2012/7/24
N2 - Mutations in the proline/tyrosine-nuclear localization signal (PY-NLS) of the Fused in Sarcoma protein (FUS) cause amyotrophic lateral sclerosis (ALS). Here we report the crystal structure of the FUS PY-NLS bound to its nuclear import receptor Karyopherinβ2 (Kapβ2; also known as Transportin). The FUS PY-NLS occupies the structurally invariant C-terminal arch of Kapβ2, tracing a path similar to that of other characterized PY-NLSs. Unlike other PY-NLSs, which generally bind Kapβ2 in fully extended conformations, the FUS peptide is atypical as its central portion forms a 2.5-turn α-helix. The Kapβ2-binding epitopes of the FUS PY-NLS consist of an N-terminal PGKM hydrophobic motif, a central arginine-rich α-helix, and a C-terminal PY motif. ALS mutations are found almost exclusively within these epitopes. Each ALS mutation site makes multiple contacts with Kapβ2 and mutations of these residues decrease binding affinities for Kapβ2 (KD for wild-type FUS PY-NLS is 9.5 nM) up to ninefold. Thermodynamic analyses of ALS mutations in the FUS PY-NLS show that the weakening of FUSKapβ2 binding affinity, the degree of cytoplasmic mislocalization, and ALS disease severity are correlated.
AB - Mutations in the proline/tyrosine-nuclear localization signal (PY-NLS) of the Fused in Sarcoma protein (FUS) cause amyotrophic lateral sclerosis (ALS). Here we report the crystal structure of the FUS PY-NLS bound to its nuclear import receptor Karyopherinβ2 (Kapβ2; also known as Transportin). The FUS PY-NLS occupies the structurally invariant C-terminal arch of Kapβ2, tracing a path similar to that of other characterized PY-NLSs. Unlike other PY-NLSs, which generally bind Kapβ2 in fully extended conformations, the FUS peptide is atypical as its central portion forms a 2.5-turn α-helix. The Kapβ2-binding epitopes of the FUS PY-NLS consist of an N-terminal PGKM hydrophobic motif, a central arginine-rich α-helix, and a C-terminal PY motif. ALS mutations are found almost exclusively within these epitopes. Each ALS mutation site makes multiple contacts with Kapβ2 and mutations of these residues decrease binding affinities for Kapβ2 (KD for wild-type FUS PY-NLS is 9.5 nM) up to ninefold. Thermodynamic analyses of ALS mutations in the FUS PY-NLS show that the weakening of FUSKapβ2 binding affinity, the degree of cytoplasmic mislocalization, and ALS disease severity are correlated.
KW - Lou Gehrig's disease
KW - Nucleocytoplasmic transport
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U2 - 10.1073/pnas.1207247109
DO - 10.1073/pnas.1207247109
M3 - Article
C2 - 22778397
AN - SCOPUS:84864366184
SN - 0027-8424
VL - 109
SP - 12017
EP - 12021
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 30
ER -