We have identified an interaction between stefin B and the histones. Increased expression of stefin B in the nucleus influenced processing of CUX1 transcription factor, and as a consequence of diminished cleavage of CUX1, delayed cell cycle progression was determined. Interaction of stefin B with the truncated form of cathepsin L in the nucleus was confirmed by FRET experiments in the living cells. Stefin B could play an important role in regulating the proteolytic activity of cathepsin L in the nucleus, protecting substrates such as transcription factors from its proteolytic processing.
COBISS.SI-ID: 23338023
We have shown that endogenous stefin B formed smaller, occasional cytoplasmic aggregates and inhibition of the proteasome led to an increase in the amount of the endogenous protein within the cells and also increased its aggregation. Stefin B aggregates also co-localized with LC3 and the p62, markers of autophagy. Stefin B -positive cytoplasmic aggregates were partially co-localized with ubiquitin, proteasome subunits S20 and S26 and components of cytoskeleton using confocal microscopy.
COBISS.SI-ID: 23321639