Annotation inferences using phylogenetic trees
Serpins in the Caenorhabditis elegans genome.
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Primary comparative sequence analysis documents unusual nematode serpin architectures. The available abstract does not identify C28G1.2 specifically or demonstrate its function.
"Some appear
complete, some show extensive deletions, and others appear to contain only the
C-terminal part of the known serpin fold"
SRP-2 is a cross-class inhibitor that participates in postembryonic development of the nematode Caenorhabditis elegans: initial characterization of the clade L serpins.
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The C. elegans clade L serpins lack N-terminal signal peptides and are intracellular; SRP-2 is a cross-class inhibitor of granzyme B and lysosomal cathepsins.
"they lack typical N-terminal signal peptides and reside intracellularly"
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The nine srp genes characterised in this study are a tandem array on chromosome V. C28G1.2 is on chromosome X, so it is not one of these nine genes.
"revealed nine serpin genes, tandemly arrayed on chromosome V"
An intracellular serpin regulates necrosis by inhibiting the induction and sequelae of lysosomal injury.
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The paralog SRP-6 is an intracellular serpin that inhibits calpains and lysosomal cysteine peptidases and protects against necrosis.
"the C. elegans intracellular serpin, SRP-6, exhibits a prosurvival function by blocking necrosis"
The aggregation-prone intracellular serpin SRP-2 fails to transit the ER in Caenorhabditis elegans.
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C. elegans serpins lack signal peptides and are cytoplasmic. Only SRP-1, -2, -3, -6 and -7 are full-length inhibitors; the others are pseudogenes or noninhibitory variants.
"However, only SRP-1 , SRP-2 , SRP-3 , SRP-6 , and SRP-7 are synthesized as full-length proteins and serve as bona fide proteinase inhibitors, with the rest being transcribed pseudogenes or noninhibitory variants"
UniProt sequence and serpin-domain annotation for Q18287
PANTHER tree placement, serpin architecture and signal-peptide analysis of C28G1.2
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C28G1.2 lacks the hinge and reactive-centre loop present in its inhibitory paralogs.
"In every local alignment, the paralog's hinge/reactive-centre-loop segment has no counterpart in Q18287"
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C28G1.2 sits within the Caenorhabditis intracellular serpin duplication clade and has no characterised ortholog.
"No ortholog outside Caenorhabditis was placed with it, so no experimentally characterised ortholog exists"
UniProt identification of the collagen-chaperone donor
Frozen exact-input ProtNLM output and UniProt sequence for Q18287