Robert Caspary

Johann Xaver Robert Caspary (29 January 1818, Königsberg – 18 September 1887) was a German botanist.

He studied theology and philosophy at the University of Königsberg and was educated in sciences at the University of Bonn. Among his influences at Bonn were zoologist Georg August Goldfuss, astronomer Friedrich Wilhelm August Argelander and botanist Ludolph Christian Treviranus. Afterwards, he spent considerable time in England studying marine and freshwater algae. From 1851 he served as a lecturer at the University of Berlin, where he worked closely with Alexander Braun. In 1859 he returned to Königsberg as a professor of botany and director of the botanical garden.

He specialized in the study of aquatic plants, including extensive systematic research involving the family Nymphaeaceae (water lilies). He made significant contributions in the fields of plant anatomy and morphology, being especially interested in growth of the trees and the structure of vascular tissue in plants. His name is associated with the "Casparian strip", defined as a secondary thickening in many endodermal cells in the form of a continuous band or strip on the radial and transverse walls.

Caspase 11

Murine caspase-11, and its human homologs caspase-4 and caspase-5, are mammalian intracellular receptor proteases activated by TLR4 and TLR3 signaling during the innate immune response. Caspase-11, also termed the non-canonical inflammasome, is activated by TLR3/TLR4-TRIF signaling and directly binds cytosolic lipopolysaccharide (LPS), a major structural element of Gram-negative bacterial cell walls. Activation of caspase-11 by LPS is known to cause the activation of other caspase proteins, leading to septic shock, pyroptosis, and often organismal death.

History

LPS is a known activator of innate immune responses. Extracellular LPS binds specifically to the cell surface receptor TLR4. LPS binding to TLR4 subsequently causes initiation of the MyD88 and TRIF signaling pathways, leading to expression of pro-inflammatory molecules and cytokines. These inflammatory mediators cause host toxic shock and sepsis as a result of an overactive immune response to LPS. Until recently, TLR4 was considered the sole receptor for LPS.

Caspase 7

Caspase-7, apoptosis-related cysteine peptidase, also known as CASP7, is a human protein encoded by the CASP7 gene. CASP7 orthologs have been identified in nearly all mammals for which complete genome data are available. Unique orthologs are also present in birds, lizards, lissamphibians, and teleosts.

Function

Caspase-7 is a member of the caspase (cysteine aspartate protease) family of proteins, and has been shown to be an executioner protein of apoptosis. Sequential activation of caspases plays a central role in the execution-phase of cell apoptosis. Caspases exist as inactive proenzymes that undergo proteolytic processing by upstream caspases (caspase-8, -9) at conserved aspartic residues to produce two subunits, large and small, that dimerize to form the active enzyme in the form of a heterotetramer. The precursor of this caspase is cleaved by caspase 3, caspase 10, and caspase 9. It is activated upon cell death stimuli and induces apoptosis. Alternative splicing results in four transcript variants, encoding three distinct isoforms.