Expression and proteasomal degradation of the major vault protein (MVP) in mammalian oocytes and zygotes.
Major vault protein (MVP), also called lung resistance-related protein is a ribonucleoprotein comprising a major part (>70%) of the vault particle. The function of vault particle is not known, although it appears to be involved in multi-drug resistance and cellular signaling. Here we show that MVP is expressed in mammalian, porcine, and human ova and in the porcine preimplantation embryo. MVP was identified by matrix-assisted laser-desorption ionization-time-of-flight (MALDI-TOF) peptide sequencing and Western blotting as a protein accumulating in porcine zygotes cultured in the presence of specific proteasomal inhibitor MG132. MVP also accumulated in poor-quality human oocytes donated by infertile couples and porcine embryos that failed to develop normally after in vitro fertilization or somatic cell nuclear transfer. Normal porcine oocytes and embryos at various stages of preimplantation development showed mostly cytoplasmic labeling, with increased accumulation of vault particles around large cytoplasmic lipid inclusions and membrane vesicles. Occasionally, MVP was associated with the nuclear envelope and nucleolus precursor bodies. Nucleotide sequences with a high degree of homology to human MVP gene sequence were identified in porcine oocyte and endometrial cell cDNA libraries. We interpret these data as the evidence for the expression and ubiquitin-proteasome-dependent turnover of MVP in the mammalian ovum. Similar to carcinoma cells, MVP could fulfill a cell-protecting function during early embryonic development.
Sutovsky
Peter
P
Department of Animal Science, University of Missouri, Columbia, MO 65203, USA. SutovskyP@missouri.edu
Manandhar
Gaurishankar
G
Laurincik
Jozef
J
Letko
Juraj
J
Caamaño
Jose Nestor
JN
Day
Billy N
BN
Lai
Liangxue
L
Prather
Randall S
RS
Sharpe-Timms
Kathy L
KL
Zimmer
Randall
R
Sutovsky
Miriam
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western / Q000379:methods; D018929:Cell Culture Techniques; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005307:Fertilization in Vitro; D005455:Fluorescent Antibody Technique; D006801:Humans; D008322:Mammals / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D009865:Oocytes / Q000737:chemistry / Q000378:metabolism*; D009866:Oogenesis; D020539:Sequence Analysis, Protein; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013552:Swine; D020394:Vault Ribonucleoprotein Particles / Q000378:metabolism*; D015053:Zygote / Q000378:metabolism*; D000099187:Major Vault Protein
D020394:Vault Ribonucleoprotein Particles; D000099187:Major Vault Protein