A simple and parsimonious model which originated from the Weibull frequency distribution was proposed to describe nonlinear survival curves of spores. This model was suitable for downward concavity curves (Bacillus cereus and Bacillus pumilus), as well as for upward concavity curves (Clostridium botulinum). It was shown that traditional F values calculated from this new model were no longer additive, to such an extent that a heat treatment should be better characterized by the obtained decimal reduction of spores. A modified Bigelow method was then proposed to assess this decade reduction or to optimize the heat treatment for a target reduction ratio.

Striatin is an intracellular protein characterized by four protein-protein interaction domains, a caveolinbinding motif, a coiled-coil structure, a calmodulinbinding domain, and a WD repeat domain, suggesting that it is a signaling or a scaffold protein. Down-regulation of striatin, which is expressed in a few subsets of neurons, impairs the growth of dendrites as well as rat locomotor activity (Bartoli, M., Ternaux, J. P., Forni, C., Portalier, P., Salin, P., Amalric, M., and Monneron, A. (1999) J. Neurobiol. 40, 234 -243). Zinedin, a "novel" protein described here, and SG2NA share with striatin identical protein-protein interaction domains and the same overall domain structure. A phylogenetic analysis supports the hypothesis that they constitute a multigenic family deriving from an ancestral gene. DNA probes and antibodies raised against specific domains of each protein showed that zinedin is mainly expressed in the central nervous system, whereas SG2NA, of more widespread occurrence, is mainly expressed in the brain and muscle. All three proteins are both cytosolic and membrane-bound. All three bind calmodulin in the presence of Ca 2؉ . In rat brain, SG2NA and striatin are generally not found in the same neurons. Both localize to the soma and dendrites, suggesting that they share a similar type of addressing and closely related functions.Striatin is an intracellular protein mostly present in neurons of mammalian basal ganglia and cranial and spinal motor nuclei (1, 2). Electron microscopy showed that it is present in the somato-dendritic compartment of neurons, especially in dendritic spines (1). Brain fractionation shows that striatin is both cytosolic and associated with membranes. This multimodular protein possesses, from the N to the C terminus, four domains mediating protein-protein interactions: a caveolinbinding domain (aa 1 55-63) (3), a putative coiled-coil structure (aa 70 -116), a Ca 2ϩ -calmodulin (CaM)-binding domain (aa 149 -166) (4),and a WD repeat domain (aa 419 -780). The WD repeat family is composed of homologous, structurally related, but functionally diverse proteins able to organize multiple simultaneous or consecutive protein-protein interactions (5). The richness of striatin in domains mediating protein-protein interactions suggests that striatin is both a signaling protein and a multimodular platform protein. A study aimed at elucidating the function of striatin revealed two sets of data demonstrating its central role both in embryonic neurons and in adult brain (6). On the one hand, we showed that the expression of striatin is essential for the maintenance and growth of dendrites in rat embryonic motoneurons in culture. On the other hand, we showed that striatin is involved in the control of motor function in adult rats. Albeit a quantitatively minor protein, striatin thus appears to play major cellular and physiological roles.We have previously reported that the sequence of SG2NA, a 713 aa, supposedly nuclear protein discovered by Muro et al. (7), is 80% similar to and 66% identical...

C-low-threshold mechanoreceptors (C-LTMRs) are unique among C-unmyelinated primary sensory neurons. These neurons convey two opposite aspects of touch sensation: a sensation of pleasantness, and a sensation of injury-induced mechanical pain. Here, we show that TAFA4 is a specific marker of C-LTMRs. Genetic labeling in combination with electrophysiological recordings show that TAFA4+ neurons have intrinsic properties of mechano-nociceptors. TAFA4-null mice exhibit enhanced mechanical and chemical hypersensitivity following inflammation and nerve injury as well as increased excitability of spinal cord lamina IIi neurons, which could be reversed by intrathecal or bath application of recombinant TAFA4 protein. In wild-type C57/Bl6 mice, intrathecal administration of TAFA4 strongly reversed carrageenan-induced mechanical hypersensitivity, suggesting a potent analgesic role of TAFA4 in pain relief. Our data provide insights into how C-LTMR-derived TAFA4 modulates neuronal excitability and controls the threshold of somatic sensation.