ALS-associated mutations in TDP-43 increase its stability and promote TDP-43 complexes with FUS/TLS

作者：Ling Shuo Chien; Albuquerque Claudio P; Han Joo Seok; Lagier Tourenne Clotilde; Tokunaga Seiya; Zhou Huilin; Cleveland Don W^*

来源：Proceedings of the National Academy of Sciences, 2010, 107(30): 13318-13323.

DOI：10.1073/pnas.1008227107

• mass spectrometry
• protein stability
• amyotrophic lateral sclerosis
• microRNA
• ribonucleoproteins

Dominant mutations in two functionally related DNA/RNA-binding proteins, trans-activating response region (TAR) DNA-binding protein with a molecular mass of 43 KDa (TDP-43) and fused in sarcoma/translocation in liposarcoma (FUS/TLS), cause an inherited form of ALS that is accompanied by nuclear and cytoplasmic aggregates containing TDP-43 or FUS/TLS. Using isogenic cell lines expressing wild-type or ALS-linked TDP-43 mutants and fibroblasts from a human patient, pulse-chase radiolabeling of newly synthesized proteins is used to determine, surprisingly, that ALS-linked TDP-43 mutant polypeptides are more stable than wild-type TDP-43. Tandem-affinity purification and quantitative mass spectrometry are used to identify TDP-43 complexes not only with heterogeneous nuclear ribonucleoproteins family proteins, as expected, but also with components of Drosha microprocessor complexes, consistent with roles for TDP-43 in both mRNA processing and microRNA biogenesis. A fraction of TDP-43 is shown to be complexed with FUS/TLS, an interaction substantially enhanced by TDP-43 mutants. Taken together, abnormal stability of mutant TDP-43 and its enhanced binding to normal FUS/TLS imply a convergence of pathogenic pathways from mutant TDP-43 and FUS/TLS in ALS.

• 出版日期2010-7-27