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Query: UNIPROT:P50502 (Hip)
 7,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Hedgehog signalling pathway is essential for the development of diverse tissues during embryogenesis. Signalling is activated by binding of Hedgehog protein to the multipass membrane protein Patched (Ptc). We have now identified a novel component in the vertebrate signalling pathway, which we name Hip (for Hedgehog-interacting protein) because of its ability to bind Hedgehog proteins. Hip encodes a membrane glycoprotein that binds to all three mammalian Hedgehog proteins with an affinity comparable to that of Ptc-1. Hip-expressing cells are located next to cells that express each Hedgehog gene. Hip expression is induced by ectopic Hedgehog signalling and is lost in Hedgehog mutants. Thus, Hip, like Ptc-1, is a general transcriptional target of Hedgehog signalling. Overexpression of Hip in cartilage, where Indian hedgehog (Ihh) controls growth, leads to a shortened skeleton that resembles that seen when Ihh function is lost (B. St-Jacques, M. Hammerschmidt & A.P.M., in preparation). Our findings support a model in which Hip attenuates Hedgehog signalling as a result of binding to Hedgehog proteins: a negative regulatory feedback loop established in this way could thus modulate the responses to any Hedgehog signal.
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PMID:Vertebrate Hedgehog signalling modulated by induction of a Hedgehog-binding protein. 1005 Aug 55

The function of Tic40 during chloroplast protein import was investigated. Tic40 is an inner envelope membrane protein with a large hydrophilic domain located in the stroma. Arabidopsis null mutants of the atTic40 gene were very pale green and grew slowly but were not seedling lethal. Isolated mutant chloroplasts imported precursor proteins at a lower rate than wild-type chloroplasts. Mutant chloroplasts were normal in allowing binding of precursor proteins. However, during subsequent translocation across the inner membrane, fewer precursors were translocated and more precursors were released from the mutant chloroplasts. Cross-linking experiments demonstrated that Tic40 was part of the translocon complex and functioned at the same stage of import as Tic110 and Hsp93, a member of the Hsp100 family of molecular chaperones. Tertiary structure prediction and immunological studies indicated that the C-terminal portion of Tic40 contains a TPR domain followed by a domain with sequence similarity to co-chaperones Sti1p/Hop and Hip. We propose that Tic40 functions as a co-chaperone in the stromal chaperone complex that facilitates protein translocation across the inner membrane.
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PMID:Tic40, a membrane-anchored co-chaperone homolog in the chloroplast protein translocon. 1280 12

To clarify the pathway of anaerobic sulfur oxidation coupled with dissimilatory ferric iron reduction in Acidithiobacillus ferrooxidans strain CCM 4253 cells, we monitored their energy metabolism gene transcript profiles. Several genes encoding electron transporters involved in aerobic iron and sulfur respiration were induced during anaerobic growth of ferrous iron-grown cells. Most sulfur metabolism genes were either expressed at the basal level or their expression declined. However, transcript levels of genes assumed to be responsible for processing of elemental sulfur and other sulfur intermediates were elevated at the beginning of the growth period. In contrast, genes with predicted functions in formation of hydrogen sulfide and sulfate were significantly repressed. The main proposed mechanism involves: outer membrane protein Cyc2 (assumed to function as a terminal ferric iron reductase); periplasmic electron shuttle rusticyanin; c4-type cytochrome CycA1; the inner membrane cytochrome bc1 complex I; and the quinone pool providing connection to the sulfur metabolism machinery, consisting of heterodisulfide reductase, thiosulfate:quinone oxidoreductase and tetrathionate hydrolase. However, an alternative mechanism seems to involve a high potential iron-sulfur protein Hip, c4-type cytochrome CycA2 and inner membrane cytochrome bc1 complex II. Our results conflict with findings regarding the type strain, indicating strain- or phenotype-dependent pathway variation.
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PMID:Are there multiple mechanisms of anaerobic sulfur oxidation with ferric iron in Acidithiobacillus ferrooxidans? 2692 14