Major Vault Protein (MVP)

Major vault protein is a lung resistance-related protein. Vaults are multi-subunit structures that may be involved in nucleo-cytoplasmic transport. This protein mediates drug resistance, perhaps via a transport process. It is widely distributed in normal tissues, and overexpressed in multidrug-resistant cancer cells.

The protein overexpression is a potentially useful marker of clinical drug resistance. This gene produces two transcripts by using two alternative exon 2 sequences; however, the open reading frames are the same in both transcripts.L-MVP, that contains a 41-bp stretch in the 5-prime region that is intronic in the shorter S-MVP splice variant. This 41-bp stretch introduces an upstream ORF encoding a deduced 18-amino acid peptide.