Bacteriocins are a kind of ribosomal synthesized antimicrobial peptides produced by bacteria, which can kill or inhibit bacterial strains closely-related or non-related to produced bacteria, but will not harm the bacteria themselves by specific immunity proteins. Bacteriocins become one of the weapons against microorganisms due to the specific characteristics of large diversity of structure and function, natural resource, and being stable to heat. Many recent studies have purified and identified bacteriocins for application in food technology, which aims to extend food preservation time, treat pathogen disease and cancer therapy, and maintain human health. Therefore, bacteriocins may become a potential drug candidate for replacing antibiotics in order to treat multiple drugs resistance pathogens in the future. This review article summarizes different types of bacteriocins from bacteria. The latter half of this review focuses on the potential applications in food science and pharmaceutical industry.

Thirteen mutant rhodopsins responsible for autosomal dominant retinitis pigmentosa (ADRP) have been produced by transfection of cloned cDNA into tissue culture cells. Three mutants [class I: Phe45 --Leu, termination (deletion of C-terminal positions 344-348), and Pro-347 --Leul resemble wild-type rhodopsin in yield, regenerability with 11-cis-retinal, and plasma membrane localization. Ten mutants Met, His, Thr-58 --Arg, Val-87 -* Asp, Gly-89 Asp, Gly-106 -Trp, Arg-135 --Leu, Arg-135 Trp, Tyr-178 -+ Cys, and Gly] accumulate to significantly lower levels, regenerate with 11-cis-retinal variably or not at all, and are transported inefficiently to the plasma membrane, remaining primarily in the endoplasmic reticulum. These data suggest that there are at least two distinct biochemical defects associated with different rhodopsin mutants in ADRP.Retinitis pigmentosa (RP) is a group of inherited disorders that cause a progressive loss of retinal function. The hallmarks ofRP are decreased rod sensitivity, progressive loss of visual fields, a diminished electroretinographic response referable to photoreceptors, and characteristic pigmentary deposits in the retina (1).Recently, some patients with autosomal dominant RP (ADRP) were found to carry mutations in the gene encoding rhodopsin, the visual pigment mediating rod vision (2-5). The mutations cosegregate with RP and are absent from control populations with normal vision. In a previous study of 161 unrelated families with ADRP, 39 were found to carry 1 of 13 different point mutations in the rhodopsin coding region (5). The goal of the present study is to define the biochemical differences between wild-type (wt) rhodopsin and the variants responsible for ADRP. For this purpose we have produced in tissue culture cells each of the 13 mutant human rhodopsins described above and determined their yield, regenerability with 11-cis-retinal, and subcellular localization. MATERIALS AND METHODSTissue Culture Expression. A rhodopsin cDNA clone was isolated from a human retina cDNA library (6, 7), and a fragment containing the entire coding region was inserted into the expression plasmid pCIS (8). In vitro mutagenesis and production of opsin after transient or stable transfection of 293S cells were performed as described (9, 10).Absorbance Spectra. Cells from 20 10-cm plates were collected 60 hr after transient transfection, and membranes were prepared as described (9) except that the final membrane pellet was solubilized in 0.3 ml of 0.1 M sodium phosphate, pH 6.5/1 mM EDTA/1% 3-[(3-cholamidopropyl)-dimethylammoniol-1-propanesulfonate (CHAPS; Sigma). The solubilized sample was regenerated with li-cis-retinal, incubated with 50 mM hydroxylamine for 30 min, and the photobleaching difference spectrum was determined (9).Immunoblotting. Membrane samples prepared from cells 60 hr after transfection were mixed with an equal volume of 2x Laemmli sample buffer (lx = 0.125 M TrisHCl, pH 6.8/4% SDS/20o glycerol/10%o 2-mercaptoethanol/0.012% bromophenol blue), resolved on a SDS/12.5%...

Cilia are present across most eukaryotic phyla and have diverse sensory and motility roles in animal physiology, cell signalling and development. Their biogenesis and maintenance depend on vesicular and intraciliary (intraflagellar) trafficking pathways that share conserved structural and functional modules. The functional units of the interconnected pathways, which include proteins involved in membrane coating as well as small GTPases and their accessory factors, were first experimentally associated with canonical vesicular trafficking. These components are, however, ancient, having been co-opted by the ancestral eukaryote to establish the ciliary organelle, and their study can inform us about ciliary biology in higher organisms.

The translocation of the microtubule-organizing center (MTOC) toward the nascent immune synapse (IS) is an early step in lymphocyte activation initiated by T cell receptor (TCR) signaling. The molecular mechanisms that control the physical movement of the lymphocyte MTOC remain largely unknown. We have studied the role of the dynein–dynactin complex, a microtubule-based molecular motor, in the process of T cell activation during T cell antigen–presenting cell cognate immune interactions. Impairment of dynein–dynactin complex activity, either by overexpressing the p50-dynamitin component of dynactin to disrupt the complex or by knocking down dynein heavy chain expression to prevent its formation, inhibited MTOC translocation after TCR antigen priming. This resulted in a strong reduction in the phosphorylation of molecules such as ζ chain–associated protein kinase 70 (ZAP70), linker of activated T cells (LAT), and Vav1; prevented the supply of molecules to the IS from intracellular pools, resulting in a disorganized and dysfunctional IS architecture; and impaired interleukin-2 production. Together, these data reveal MTOC translocation as an important mechanism underlying IS formation and sustained T cell signaling.

Fungal secondary metabolites (SMs) are an important source of medically valuable compounds. Genome projects have revealed that fungi have many SM biosynthetic gene clusters that are not normally expressed. To access these potentially valuable, cryptic clusters, we have developed a heterologous expression system in Aspergillus nidulans. We have developed an efficient system for amplifying genes from a target fungus, placing them under control of a regulatable promoter, transferring them into A. nidulans and expressing them. We have validated this system by expressing non-reducing polyketide synthases of Aspergillus terreus and additional genes required for compound production and release. We have obtained compound production and release from six of these NR-PKSs and have identified the products. To demonstrate that the procedure allows transfer and expression of entire secondary metabolite biosynthetic pathways, we have expressed all the genes of a silent A. terreus cluster and demonstrate that it produces asperfuranone. Further, by expressing the genes of this pathway in various combinations, we have clarified the asperfuranone biosynthetic pathway. We have also developed procedures for deleting entire A. nidulans SM clusters. This allows us to remove clusters that might interfere with analyses of heterologously expressed genes and to eliminate unwanted toxins.

Coordinated microtubule and microfilament changes are essential for the morphological development of neurons; however, little is know about the underlying molecular machinery linking these two cytoskeletal systems. Similarly, the indispensable role of RhoGTPase family proteins has been demonstrated, but it is unknown how their activities are specifically regulated in different neurites. In this paper, we show that the cytoplasmic dynein light chain Tctex-1 plays a key role in multiple steps of hippocampal neuron development, including initial neurite sprouting, axon specification, and later dendritic elaboration. The neuritogenic effects elicited by Tctex-1 are independent from its cargo adaptor role for dynein motor transport. Finally, our data suggest that the selective high level of Tctex-1 at the growth cone of growing axons drives fast neurite extension by modulating actin dynamics and also Rac1 activity.

The light-sensing organelle of the vertebrate rod photoreceptor, the outer segment (OS), is a modified cilium containing approximately 1,000 stacked disc membranes that are densely packed with visual pigment rhodopsin. The mammalian OS is renewed every ten days; new discs are assembled at the base of the OS by a poorly understood mechanism. Our results suggest that discs are formed and matured in a process that involves specific phospholipid-directed vesicular membrane targeting. Rhodopsin-laden vesicles in the OS axonemal cytoplasm fuse with nascent discs that are highly specialized with abundant phosphatidylinositol 3-phosphate (PI3P). This membrane coupling is regulated by the FYVE domain-containing protein, SARA, through its direct interaction with PI3P, rhodopsin, and SNARE protein syntaxin 3. Our model, in contrast to the previously proposed evagination model, suggests that the vesicular delivery of rhodopsin in the OS concentrates rhodopsin into discs, and this process directly participates in disc biogenesis.

Humans possess the remarkable ability to perceive color, shape, and motion, and to differentiate between light intensities varied by over nine orders of magnitude. Phototransduction—the process in which absorbed photons are converted into electrical responses—is the first stage of visual processing, and occurs in the outer segment, the light-sensing organelle of the photoreceptor cell. Studies of genes linked to human inherited blindness have been crucial to understanding the biogenesis of the outer segment and membrane-trafficking of photoreceptors.