DnaK/Hsp70 chaperones form oligomers of poorly understood structure and functional significance. Site-specific proteolysis and crosslinking were used to probe the architecture of oligomers formed by the endoplasmic reticulum (ER) Hsp70, BiP. These were found to consist of adjacent protomers engaging the interdomain linker of one molecule in the substrate binding site of another, attenuating the...

BiP is the predominant DnaK/Hsp70-type chaperone protein in the ER. It is required for folding and assembling newly synthesized ER client proteins, yet having too much BiP inhibits folding. In this issue, Chambers et al. (2012. J. Cell Biol. doi:10.1083/jcb.201202005) report that ADP ribosylation of BiP provides a reversible switch that fine tunes BiP activity according to need.

Men court-mandated to attend a batterer's intervention program (BIP) were evaluated to determine whether pre-BIP readiness to change and the presence of partner violence subtypes predicted BIP completion, criminal recidivism, and postadjudication partner violence 6 months post-BIP. Of the 199 subject sample, 40% did not complete BIP. Four readiness-to-change clusters were found, with most men (...

Endoplasmic reticulum (ER) stress-induced activation of ATF6, an ER membrane-bound transcription factor, requires a dissociation step from its inhibitory regulator, BiP. It has been generally postulated that dissociation of the BiP-ATF6 complex is a result of the competitive binding of misfolded proteins generated during ER stress. Here we present evidence against this model and for an active r...

Previous studies have demonstrated that overexpression of GRP78/BiP, an endoplasmic reticulum (ER)-resident molecular chaperone, in mammalian cells inhibits the secretion of specific coagulation factors. However, the effects of GRP78/BiP on activation of the coagulation cascade leading to thrombin generation are not known. In this study, we examined whether GRP78/BiP overexpression mediates cel...

The aim of the present study was to identify main risk factors and treatment needs batterer intervention program (BIP) participants with alcohol drug abuse problems (ADAPs), beyond issues strictly related their substance abuse, taking into account four sets variables: sociodemographic (i.e., age, educational level, income, employment, immigrant status); personality disorders psychological adjus...

BINDING PROTEIN (BiP) is a major chaperone in the endoplasmic reticulum (ER) lumen, and this study shows that BiP binds to the C-terminal tail of the stress sensor/transducer bZIP28, a membrane-associated transcription factor, retaining it in the ER under unstressed conditions. In response to ER stress, BiP dissociates from bZIP28, allowing it to be mobilized from the ER to the Golgi where it i...

Drosophila Fic (dFic) mediates AMPylation, a covalent attachment of adenosine monophosphate (AMP) from ATP to hydroxyl side chains of protein substrates. Here, we identified the endoplasmic reticulum (ER) chaperone BiP as a substrate for dFic and mapped the modification site to Thr-366 within the ATPase domain. The level of AMPylated BiP in Drosophila S2 cells is high during homeostasis, wherea...

759 he discovery of immunoglob-ulin heavy chain binding protein (BiP) in antibody-producing cells (Morrison and Scharff, 1975; Haas and Wabl, 1984) had researchers trying to assign an immune function to it. In one theory, BiP was thought to regulate allelic exclusion of heavy and light chain genes (Wabl and Steinberg, 1982). Part of the theory assumed that BiP neutralized a proposed heavy chain...

BiP overexpression improves leaf water relations during droughts and delays drought-induced leaf senescence. However, whether BiP controls cellular homeostasis under drought conditions or simply delays dehydration-induced leaf senescence as the primary cause for water stress tolerance remains to be determined. To address this issue, we examined the drought-induced transcriptomes of BiP-overexpr...