Prothymosin alpha fragmentation in apoptosis.
We observed fragmentation of an essential proliferation-related human nuclear protein prothymosin alpha in the course of apoptosis induced by various stimuli. Prothymosin alpha cleavage occurred at the DDVD(99) motif. In vitro, prothymosin alpha could be cleaved at D(99) by caspase-3 and -7. Caspase hydrolysis disrupted the nuclear localization signal of prothymosin alpha and abrogated the ability of the truncated protein to accumulate inside the nucleus. Prothymosin alpha fragmentation may therefore be proposed to disable intranuclear proliferation-related function of prothymosin alpha in two ways: by cleaving off a short peptide containing important determinants, and by preventing active nuclear uptake of the truncated protein.
Evstafieva
A G
AG
Belozersky Institute of Physico-Chemical Biology, Center of Molecular Medicine, Moscow State University, Moscow, Russia.
Belov
G A
GA
Kalkum
M
M
Chichkova
N V
NV
Bogdanov
A A
AA
Agol
V I
VI
Vartapetian
A B
AB
D017209:Apoptosis; D001665:Binding Sites; D053148:Caspase 3; D053179:Caspase 7; D020169:Caspases; D053938:DNA Fragmentation; D006367:HeLa Cells; D006801:Humans; D019913:Nuclear Localization Signals; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics*; D013947:Thymosin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000235:genetics; D014162:Transfection
D019913:Nuclear Localization Signals; D011498:Protein Precursors; C040782:prothymosin alpha; D013947:Thymosin; C505407:CASP3 protein, human; C505520:CASP7 protein, human; D053148:Caspase 3; D053179:Caspase 7; D020169:Caspases