Most animals rely on circulating hemocytes as cellular effectors of immunity. These cells traditionally have been characterized by morphology, function, and cellular contents. Morphological descriptions use granule differences and cell shapes; functional descriptions rely on phagocytic ability and oxygen transport; and cellular content descriptions include cytochemical features and key enzymes.
View Article and Find Full Text PDFProteasomes are multisubunit protease complexes which are partly responsible for metabolism of intracellular, ubiquitinylated proteins. Vertebrates have adapted a second and specialized structure responsible for the generation of peptides presented to the adaptive immune system and is thus, commonly referred to as the immunoproteasome. This complex is assembled from paralogous copies of subunits belonging to the constitutive, housekeeping proteasome.
View Article and Find Full Text PDFC3, C4, and C5 are thiolester-containing proteins (TEPs) of vertebrate complement. The identification of the molecular origin of the TEP family, and more specifically the ancestor protein of complement components C3, C4, and C5, remains a fundamental question. The prevailing paradigm suggests that duplication and divergence of these proteins occurred after the deuterostome split in phylogeny.
View Article and Find Full Text PDFSome sea anemones possess structures called acrorhagi at the base of the tentacles. The acrorhagi are utilized solely for aggression. Acrorhagial aggression involves very exquisite intra- and interspecific recognition.
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