Stable Isotopic Labeling Studies to Determine the Protein Turnover within the Nuclear Pore Nup107-160 Subcomplex

摘要

The nuclear pore complex (NPC) is the principal passageway for nucleocytoplasmic macromolecular traffic. It is composed of approx30 proteins, termed nucleoporins (Nups), organized into a pseudo-symmetric structure with a two-fold plane quasi-parallel to the nuclear envelope and an eight-fold axis of symmetry across the nucleo-cytoplasmic axis. In higher eukaryotic cells, the NPC disassembles into subcomplexes during open mitosis that serve as building blocks for NPC's during telophase. We previously showed that the Nup107-160 subcomplex, a core building block of the NPC, remains intact during cell cycle. Here, we present our studies of the relative turnovers within this subcomplex. We utilized metabolic labeling and mass spectrometry to simultaneously determine the half-lives of all the members of the Nup107-160 subcomplex.