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)

Eukaryotes respond to the presence of unfolded protein in the endoplasmic reticulum (ER) by up-regulating the transcription of genes encoding ER protein chaperones, such as BiP. We have isolated a novel human cDNA encoding a homolog to Saccharomyces cerevisiae Ire1p, a proximal sensor for this signal transduction pathway in yeast. The gene product hIre1p is a type 1 transmembrane protein containing a cytoplasmic domain that is highly conserved to the yeast counterpart having a Ser/Thr protein kinase domain and a domain homologous to RNase L. However, the luminal domain has extensively diverged from the yeast gene product. hIre1p expressed in mammalian cells displayed intrinsic autophosphorylation activity and an endoribonuclease activity that cleaved the 5' splice site of yeast HAC1 mRNA, a substrate for the endoribonuclease activity of yeast Ire1p. Overexpressed hIre1p was localized to the ER with particular concentration around the nuclear envelope and some colocalization with the nuclear pore complex. Expression of Ire1p mRNA was autoregulated through a process that required a functional hIre1p kinase activity. Finally, overexpression of wild-type hIre1p constitutively activated a reporter gene under transcriptional control of the rat BiP promoter, whereas expression of a catalytically inactive hIre1p acted in a trans-dominant-negative manner to prevent transcriptional activation of the BiP promoter in response to ER stress induced by inhibition of N-linked glycosylation. These results demonstrate that hIre1p is an essential proximal sensor of the unfolded protein response pathway in mammalian cells.
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PMID:A stress response pathway from the endoplasmic reticulum to the nucleus requires a novel bifunctional protein kinase/endoribonuclease (Ire1p) in mammalian cells. 963 83

Antimycins are a family of natural products possessing outstanding biological activities and unique structures, which have intrigued chemists for over a half century. Of particular interest are the ring-expanded antimycins that show promising anticancer potential and whose biosynthesis remains uncharacterized. Specifically, neoantimycin and its analogs have been shown to be effective regulators of the oncogenic proteins GRP78/BiP and K-Ras. The neoantimycin structural skeleton is built on a 15-membered tetralactone ring containing one methyl, one hydroxy, one benzyl, and three alkyl moieties, as well as an amide linkage to a conserved 3-formamidosalicylic acid moiety. Although the biosynthetic gene cluster for neoantimycins was recently identified, the enzymatic logic that governs the synthesis of neoantimycins has not yet been revealed. In this work, the neoantimycin gene cluster is identified, and an updated sequence and annotation is provided delineating a nonribosomal peptide synthetase/polyketide synthase (NRPS/PKS) hybrid scaffold. Using cosmid expression and CRISPR/Cas-based genome editing, several heterologous expression strains for neoantimycin production are constructed in two separate Streptomyces species. A combination of in vivo and in vitro analysis is further used to completely characterize the biosynthesis of neoantimycins including the megasynthases and trans-acting domains. This work establishes a set of highly tractable hosts for producing and engineering neoantimycins and their C11 oxidized analogs, paving the way for neoantimycin-based drug discovery and development.
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PMID:Biosynthesis of the 15-Membered Ring Depsipeptide Neoantimycin. 2969 72