Identification of apoptotic tyrosine‐phosphorylated proteins after etoposide or retinoic acid treatment

Abstract

A main shortcoming of using HL-60 cells as a model of granulocyte-macrophage differentiation is that some cells in the differentiating population undergo apoptosis. To address this issue, we have identified which tyrosine-phosphorylated proteins are involved in apoptosis and differentiation, respectively. HL-60 cells were induced specifically to undergo apoptosis with 68 microM etoposide, and to undergo granulocytic differentiation with 1 microM retinoic acid (RA). The corresponding two-dimensional electrophoretic maps of tyrosine-phosphorylated proteins from treated cells were compared. In the 8 h etoposide-treated HL-60 cell population, 83% of the cells were apoptotic. In the 120 h RA-treated cells, 50% of the cells were apoptotic. Eighteen cytosolic and nuclear tyrosine-phosphorylated proteins were found in both the 8 h etoposide- and the 120 h RA-treated cells, but not in the proliferating HL-60 cell population. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry analyses suggested that some of the proteins may be involved in signal transduction pathways (NFkappaB, GTP-binding protein, protein disulfide isomerase, Cyclophilin A), others in cell transcriptional and translational control (hnRNP H, hnRNP L, Hsp60, Hp1, Hcc-1, 26S proteasome beta-subunit, ATP synthase beta-chain), and a third group in cell cytoskeleton organization and receptor cycling (profilin, caveolin-1). An understanding of signal transduction in apoptosis initiation by screening for tyrosine-phosphorylated proteins associated with apoptosis may provide new targets for the treatment of leukemia.

Thirty-eight-negative kinase 1 (TNK1) facilitates TNFα-induced apoptosis by blocking NF-κB activation

“…Tyrosine kinases are involved in signaling pathways that generally lead to cell survival and tumor promotion. However, recent findings indicate that protein tyrosine phosphorylation and the catalytic domain of certain tyrosine kinases play a role in the induction of apoptosis (Navakauskiene et al, 2004;Tulasne et al, 2004).…”

Proteomic analysis of head kidney tissue from high and low susceptibility families of channel catfish following challenge with Edwardsiella ictaluri

“…This protein is known to be primarily associated with cellular energy production [10] and has been shown to bind enterostatin, a peptide that regulates fat intake in rats [21]. It has also been shown to be involved in regulation of transcription and translation of tyrosine-phosphorylated cytosolic and nuclear proteins involved in the mechanisms of apoptosis during macrophage differentiation [22]. As with Fructose-1,6-bisphosphatase 1, it is unclear what role, if any, this protein might have in disease susceptibility.…”

Low-dose ionizing radiation effects on differentiation of HL-60 cells

“…In the present study, we also found significant changes in the tyrosine-phosphorylated protein profile in HL-60 cells exposed to low-dose irradiation and treated with RA after pre-irradiation (Figure 6), suggesting the importance of their role in the molecular radiation response. Our previous data clearly demonstrated dramatic changes in the pattern of cytoplasmic tyrosine-phosphorylated proteins during the formation of the granulocytic phenotype in RA-induced HL-60 cells with the appearance of a new set of such proteins associated with apoptosis [60] or involved in the control of transcription and translation [60,61]. The evident differences in the tyrosine-phosphorylated protein patterns (including ERK2) between non-irradiated and irradiated HL-60 cells induced to differentiate to monocytes were demonstrated by two-dimensional electrophoresis [21].…”