However the function of Rac1 in the nucleus remains to be elucidated. The nucleotide state of Rac1 in the nucleus could provide insight into its function in this organelle. Different studies have addressed the nucleotide state of human Rac1 in the nucleus. Using GFP fusions, it was shown that in CHO-m3 cells a constitutive active Rac1 mutant was slightly more efficiently targeted to the nucleus, in contrast to MDCK and COS-1 cells in which a constitutive active GFP-Rac1 mutant had a similar distribution as GFP-Rac1. It was also shown that a constitutive active Rac1 mutant strongly accumulates in the nucleus of HeLa cells. In contrast, studies using fluorescence resonance energy transfer -based biosensors in Swiss 3T3 fibroblasts indicate that a large pool of GFP-Rac1 in the nucleus was inactive. In C. albicans, we observed that both the constitutive active and inactive forms of Rac1 can accumulate in the nucleus in the absence of cell agitation. However, the FRAP tK of nuclear Rac1 was significantly slower than that of Rac1. In contrast, nuclear Rac1 dynamics were significantly faster, similar to that of Rac1 in the absence of its activator Dck1. These results suggest that although both activated and inactivated mutants can accumulate in the nucleus, the inactive form of Rac1 accumulates faster in C. albicans. This could be the result of increased import, decreased export and/or the increase in a nuclear anchor. Our results are consistent with the notion that Rac1 nuclear accumulation serves to sequester this protein from the plasma membrane where it normally functions, potentially targeting it for Gefitinib degradation. Due to a worldwide effort of structural genomics projects, the number of known three-dimensional protein structures rapidly increases. It is now even frequent that structures are determined prior to any knowledge of their biological function. The ability to predict details of protein function and their biological role from structure becomes thus of great importance. To date, several methods are available for this purpose. Many of them are based on the occurrence of particular clusters of residues, in protein sequence or in protein 3D structure that could give a functional role to the unknown protein. Such clusters can be also called patterns, motifs, signatures or fingerprints, and were accumulated from various protein families in freely accessible databases, such as PROSITE, PRINTS, BLOCKS, MSDmotif or FunClust. The signature search is also an effective alternative for the detection of remote protein homologues from low-similarity sequences. Lysozymes and chitinases represent an important class of polysaccharide-hydrolyzing enzymes. Chitinase enzymes catalyse the breakdown of chitin, a linear polymer found in insects, crustaceans and fungi cell walls consisting of b-1-4 linked N-acetylglucosamine, while the lysozymes hydrolyse peptidoglycans present in bacterial cell walls which contain alternating b-1-4 linked residues of GlcNAc and N-acetylmuramic acid.