Premium
TAT‐mediated endocytotic delivery of the loop deletion Bcl‐2 protein protects neurons against cell death
Author(s) -
Soane Lucian,
Fiskum Gary
Publication year - 2005
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.2005.03359.x
Subject(s) - internalization , microbiology and biotechnology , neuroprotection , biology , programmed cell death , cell culture , transduction (biophysics) , apoptosis , cell , biochemistry , neuroscience , genetics
Protein delivery mediated by protein transduction domains (PTD) such as the HIV‐1 TAT‐PTD has emerged as a promising approach for neuroprotection. The objective of this study was to generate and evaluate the neuroprotective potential of TAT fusion proteins using constructs based on Bcl‐2 anti‐death family proteins. A TAT‐Bcl‐2 construct with the loop domain deleted (TAT‐Bcl‐2Δloop) was tested for its ability to transduce neuronal cells and to promote survival. The potential mechanism of TAT‐mediated protein internalization in neural cells was also investigated. The purified TAT‐Bcl‐2Δloop binds to neural cell and rat brain mitochondria, and transduces cultured neural cell lines and primary cortical neurons when used at n m concentrations. Effective internalization of TAT‐Bcl‐2Δloop occurs at 37°C but not at 4°C, consistent with an endocytotic process. Both cell association and internalization require interaction of TAT‐Bcl‐2Δloop with cell surface heparan sulfate proteoglycans. TAT‐mediated protein delivery in neuronal cells occurs through a lipid raft‐dependent endocytotic process, inhibited by the cholesterol‐sequestering agent nystatin. Transducible loop deleted Bcl‐2 increases the survival of cortical neurons following trophic factor withdrawal and also rescues neural cell lines from staurosporine‐induced death. These results support the concept of using protein transduction of Bcl‐2 constructs for neuroprotection.