Hi Álvaro Fernández Cabrera Proteolysis by to autophagy will decrease the chance of increased false secretion depending on the antibody target sequence. Remember that starvation induced cell death is not similar to apoptosis. You should do starvation at different time points, 30 min, 60 min, 90min 120 min up to 4 hrs. Collect supernatant and do IP. If you exceed 6 hrs starvation a lot of cells die in my experience. If your protein is secreted by the induction of starvation then you should see a sequential increase in secretion on Western blot and use 6hr or 24hr starvation supernatant to prove that no trace of your protein after death of cells. For more elaboration seek similar published work on stress induced secretory protein identification by immunoprecipitation in vitro. Here is one (PMID: 30360431)

I’ve tried from 2 hours to 48 hours serum starvation and just at 24 and 48 hours I’m able to see some bands. At these time points, my cells start dying. I wonder if my protein is like “late secreted” or I am just watching my protein of interest because dead cells are releasing all their cytoplasmic content.