Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P11021 (BiP)
 2,049 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have found that expression of the Bip (immunoglobulin heavy chain binding protein)/GRP78 (glucose regulated protein 78) gene is markedly enhanced specifically among the heat shock protein (HSP) 70 gene family during the neuronal cell death of PC12 (22a) cells, that is induced by removal of nerve growth factor (NGF) and blocked by a transcription inhibitor, actinomycin D. The Bip mRNA induction is suppressed when the NGF-deprivation-dependent cell death of PC12 (22a) cells is inhibited by cAMP, cycloheximide or high K+. The Ca2+ ionophore, A23187, caused neuronal cell death accompanied by up-regulation of Bip, HSP90, and HSP70 mRNAs. In addition, a chelator of intracellular Ca2+ (BAPTA) elevated Bip mRNA and induced cell death in a low Ca2+ medium. Alterations of intracellular calcium homeostasis thus appear to induce Bip mRNA expression as well as apoptosis in PC12 (22a) cells. However, release of Ca2+ from intracellular stores by thapsigargin induced Bip mRNA expression but not cell death, indicating that Bip mRNA induction is not sufficient for neuronal death. Induction of Bip mRNA in association with apoptosis was also observed for NGF-deprived sympathetic ganglion cells in primary culture. These lines of evidence suggest that selective induction of Bip mRNA may play an important role in the programmed cell death of neurons deprived of neurotrophic factors and could be a landmark of the neuronal programmed cell death.
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PMID:Induction of Bip mRNA upon programmed cell death of differentiated PC12 cells as well as rat sympathetic neurons. 905 2

Cyclopentenone prostaglandins (PGs) are known to arrest the cell cycle at the G(1) phase in vitro and to suppress tumor growth in vivo. However, their effects on neurons are unclear. Here, we report that some cyclopentenone PGs function as neurite outgrowth-promoting factors. They promoted neurite outgrowth from PC12 cells and from dorsal root ganglion explants but only in the presence of nerve growth factor (NGF). We refer to these PGs as neurite outgrowth-promoting PGs (NEPPs). Through study of the structure-function relationship of NEPP1-10 and related compounds, we found that the cross-conjugated dienone moiety of NEPPs was essential for promoting neurite outgrowth, and NEPP10 was concluded to be the best candidate for drug development. We also investigated the intracellular mechanism of the promotion by NEPPs and obtained evidence that immunoglobulin heavy chain binding protein/glucose-regulated protein 78 (BiP/GRP78) plays a role in the promotion, based on the following observations: Antisense nucleotides for BiP/GRP78 gene blocked the promotion of neurite outgrowth; BiP/GRP78 protein level increased in response to NEPPs; and overexpression of BiP/GRP78 protein by adenoviral gene transfer promoted the neurite outgrowth by NGF.
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PMID:Facilitatory roles of novel compounds designed from cyclopentenone prostaglandins on neurite outgrowth-promoting activities of nerve growth factor. 1093 91

Sixteen clones, recently isolated from the PC12 nerve cell line, were analysed for a variety of markers and activities. Two endoplasmic reticulum (ER) luminal markers, the chaperone protein BiP and the major Ca2+ storage protein calreticulin, as well as the 40-kD rough ER membrane marker and the plus-end-directed mirotubule motor protein, kinesin, were found to be expressed at similar levels. These results suggest that the size of the ER, the function of microtubules and the capacity of the rapidly exchanging Ca2+ store do not change substantially among the clones. Other proteins expressed at comparable levels were synapsin I and IIa, members of a nerve cell-specific protein family known to bind synaptic vesicles to the cytoskeleton. In contrast, another ER membrane protein, calnexin, and the markers of secretory organelles were found to vary markedly. One clone (clone 27) completely lacked both chromogranin B and secretogranin II, the proteins contained within dense granules, and synaptophysin, a marker of clear vesicles. Other clones expressed these markers to variable and apparently mutually unrelated levels. Marked variability was observed also in the uptake of exogenous catecholamines, in their release both at rest and after stimulation, and in nerve growth factor-induced differentiation. These results provide indirect information about the mechanisms that regulate the expression of structures and activities in PC12 cells. Of particular interest is clone 27, which appears globally incompetent for regulated secretion and might therefore be a valuable tool for the study of this activity in a nerve cell.
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PMID:Differential Expression of Markers and Activities in a Group of PC12 Nerve Cell Clones. 1210 30