Major vault protein (MVP)

Major vault protein (MVP) is the principal structural component of the vault complex, a large cytosolic ribonucleoprotein particle, making up about 70–74% of its mass[1][2][4][6]. Seventy-eight MVP monomers self-assemble to create the characteristic vault structure, which is highly conserved and widely expressed in eukaryotic cells[2][4][5][6]. Vaults also contain minor proteins (vPARP, TEP1) and small non-coding RNAs. MVP is implicated in conferring multidrug resistance, likely through drug transport or sequestration mechanisms, especially in cancer cells where overexpression is frequently observed[3][5]. In cardiac and smooth muscle, MVP functions as a cell survival factor and regulates autophagic and apoptotic cell death, possibly through protein modifications that affect its interactions with partners such as MYH9 and Beclin-1[3]. MVP also binds to PTEN, PARP4, and the estrogen receptor alpha, indicating broad functional versatility[5]. Overexpression of MVP can serve as a biomarker for clinical drug resistance. Its full biological significance and regulatory mechanisms are still being elucidated, and its therapeutic targeting is challenged by structural complexity and functional redundancy.

Other names

Lung resistance-related proteinLRPVAULT1testicular secretory protein Li 30

Drug sequestration or transport affecting resistance[5]; Protein-protein interactions modulating cell death and survival[3]