The slow Wallerian degeneration protein, WldS, binds directly to VCP/p97 and partially redistributes it within the nucleus

• Published in: Molecular biology of the cell 2006-03, Vol.17 (3), p.1075-1084
• Main Authors: Laser, Heike, Conforti, Laura, Morreale, Giacomo, Mack, Till G M, Heyer, Molly, Haley, Jane E, Wishart, Thomas M, Beirowski, Bogdan, Walker, Simon A, Haase, Georg, Celik, Arzu, Adalbert, Robert, Wagner, Diana, Grumme, Daniela, Ribchester, Richard R, Plomann, Markus, Coleman, Michael P
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphatases; Amino Acid Sequence; Animals; Cell Cycle Proteins; Cell Cycle Proteins - chemistry; Cell Cycle Proteins - metabolism; Cell Nucleus; Cell Nucleus - metabolism; Cells, Cultured; Cellular Biology; Cercopithecus aethiops; Chlorocebus aethiops; COS Cells; Evolution, Molecular; HeLa Cells; Humans; Intranuclear Space; Intranuclear Space - metabolism; Life Sciences; Mice; Mice, Inbred C57BL; Molecular Sequence Data; Nerve Tissue Proteins; Nerve Tissue Proteins - chemistry; Nerve Tissue Proteins - metabolism; Nicotinamide-Nucleotide Adenylyltransferase; Nicotinamide-Nucleotide Adenylyltransferase - metabolism; Protein Binding; Protein Transport; Rats; Recombinant Fusion Proteins; Recombinant Fusion Proteins - metabolism; Ubiquitin; Ubiquitin - metabolism; Valosin Containing Protein
• ISSN: 1059-1524; 1939-4586
• DOI: 10.1091/mbc.E05-04-0375

Slow Wallerian degeneration (Wld(S)) mutant mice express a chimeric nuclear protein that protects sick or injured axons from degeneration. The C-terminal region, derived from NAD(+) synthesizing enzyme Nmnat1, is reported to confer neuroprotection in vitro. However, an additional role for the N-terminal 70 amino acids (N70), derived from multiubiquitination factor Ube4b, has not been excluded. In wild-type Ube4b, N70 is part of a sequence essential for ubiquitination activity but its role is not understood. We report direct binding of N70 to valosin-containing protein (VCP; p97/Cdc48), a protein with diverse cellular roles including a pivotal role in the ubiquitin proteasome system. Interaction with Wld(S) targets VCP to discrete intranuclear foci where ubiquitin epitopes can also accumulate. Wld(S) lacking its N-terminal 16 amino acids (N16) neither binds nor redistributes VCP, but continues to accumulate in intranuclear foci, targeting its intrinsic NAD(+) synthesis activity to these same foci. Wild-type Ube4b also requires N16 to bind VCP, despite a more C-terminal binding site in invertebrate orthologues. We conclude that N-terminal sequences of Wld(S) protein influence the intranuclear location of both ubiquitin proteasome and NAD(+) synthesis machinery and that an evolutionary recent sequence mediates binding of mammalian Ube4b to VCP.