Yeast cell cycle protein CDC48p shows full-length homology to the mammalian protein VCP and is a member of a protein family involved in secretion, peroxisome formation, and gene expression.

Yeast mutants of cell cycle gene cdc481 ar- rest as large budded cells with microtubules spreading aberrantly throughout the cytoplasm from a single spin- dle plaque . The gene was cloned and disruption proved it to be essential . The CDC48 sequence encodes a pro- tein of 92 kD that has an internal duplication of 200 amino acids and includes a nucleotide binding consensus sequence . Vertebrate VCP has a 70% identity over the entire length of the protein . Yeast Secl8p and mamma- lian N-ethylmaleimide-sensitive fusion protein, which are involved in intracellular transport, yeast Paslp,