Bacteria that infect humans and animals face a hard combat with the host´s immune system and in order to establish infection, pathogenic bacteria has evolved mechanisms to avoid being cleared from the host tissue. Many Gram-negatives carry a Type 3 secretion (T3S) system that is used to deliver effector proteins (toxins) into host cells. The toxins exhibit a broad range of intra cellular effects that has in common that they increase the chances of the bacteria to establish infection, multiply in infected tissue or spread to other tissues or hosts. The object of this study was to analyse the mechanisms behind the T3S effectors delivery into target cells. Two bacterial proteins, LcrV and YopD, which are involved in the translocation of effectors were analyzed by mutagenesis. LcrV was found to affect the efficiency of the translocation, probably by determining the size of the pore in the target cell membrane through which the effectors pass. Truncated variants of the multi-functional YopD revealed that defined regions of the protein were important for pore-formation and translocation. Effectors and translocators were demonstrated to form complexes with free acyl chains (lipids) at the bacterial surface. These complexes –termed Yop-lipid complexes, (YLC)– are released from the surface and can act as discrete units that are able to promote translocation of effectors even when separated from the bacterium from which they originate. These findings shed new light on the process of effector translocation by Yersinia and possibly by other gram-negative bacterial pathogens with a similar T3S setup.

Nedarbas – sudėtinga socialinė problema, tiesiogiai ir stipriai veikianti tiek atskirus asmenis, tiek ir visą šalį. Darbo rinkoje jaunimas, dažniau susiduria su nedarbo problema bei gauna santykinai mažą darbo užmokestį. Todėl visos Europos Sąjungos šalys, tarp jų ir Lietuva, turi vieningai spręsti jaunimo nedarbo problemą. Šio mokslinio darbo tikslas – išanalizuoti Jaunimo darbo centrų veiklą, nustatyti problemas ir pateikti rekomendacijas joms spręsti. Teorinėje šio darbo dalyje apžvelgiama darbo pasaulio kaitos tendencijos, jaunimo situacija Lietuvos ir Europos Sąjungos darbo rinkoje, analizuojami specifiniai jauno bedarbio bruožai, įsidarbinimo gebėjimai. Šioje dalyje pateikiama informacija apie Lietuvos Jaunimo darbo centrus, jų veiklą, paslaugas. Siekiant išanalizuoti Jaunimo darbo centrų veiklą, dviejuose JDC (Vilniaus ir Panevėžio) atliktas tyrimas, kurio metu apklausti 107 respondentai (JDC lankytojai). Darbe naudojamas tyrimo metodas – anketinė apklausa. / Unemployment is a very difficult social problem, directly and strongly affecting not just separate people but the whole country as well. Youth in the job market oftenly faces unemployment and gets relatively small salary. That is why all European Union countries including Lithuania must solve youth unemployment problems unitely. The aim of this study is to analize Youth Labour Centers’ (YLC) activities, determine problems and give recommendations how to solve them. In the theoretical part of this study labour work tendencies, youth situation in Lithuania and EU labour market are described, specific young uneployed persons features and employment capabilities are analized. Information about Lithuanian Youth Labour Centers, their activities and services is presented also. Seeking to analize Youth Labour Centers’ activities deeper research was made in 2 Сenters (Vilnius and Panevezys). 107 respondents were interviewed (YLC clients), research type is questionnaire. Research showed that Youth Labour Centers activities like organizing special sessions, informing youth about changes in the labour market help solving youth unemployment problems. Thus YLC activities do have some problems and in order to solve them, time, human and financial resources are needed. Gained results are important for YLC workers, clients, specialists, students because they help better understand YLC activities, arising problems and limitations. Knowing YLC limitations we can more effectively organize it’s... [to full text]