TY  - JOUR
A1  - Wendler, Petra
A1  - Enenkel, Cordula
T1  - Nuclear Transport of Yeast Proteasomes
JF  - Frontiers in molecular biosciences
N2  - Proteasomes are key proteases in regulating protein homeostasis. Their holo-enzymes are composed of 40 different subunits which are arranged in a proteolytic core (CP) flanked by one to two regulatory particles (RP). Proteasomal proteolysis is essential for the degradation of proteins which control time-sensitive processes like cell cycle progression and stress response. In dividing yeast and human cells, proteasomes are primarily nuclear suggesting that proteasomal proteolysis is mainly required in the nucleus during cell proliferation. In yeast, which have a closed mitosis, proteasomes are imported into the nucleus as immature precursors via the classical import pathway. During quiescence, the reversible absence of proliferation induced by nutrient depletion or growth factor deprivation, proteasomes move from the nucleus into the cytoplasm. In the cytoplasm of quiescent yeast, proteasomes are dissociated into CP and RP and stored in membrane-less cytoplasmic foci, named proteasome storage granules (PSGs). With the resumption of growth, PSGs clear and mature proteasomes are transported into the nucleus by Blm10, a conserved 240 kDa protein and proteasome-intrinsic import receptor. How proteasomes are exported from the nucleus into the cytoplasm is unknown.
KW  - proteasome
KW  - nuclear transport
KW  - importin
KW  - karyopherin
KW  - Blm10
KW  - proteasome storage granules
Y1  - 2019
U6  - https://doi.org/10.3389/fmolb.2019.00034
SN  - 2296-889X
VL  - 6
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  -