Bacteria adapt to different environments by regulating cell division and several conditions that modulate cell division have been documented. Understanding how bacteria transduce environmental ...signals to control cell division is critical in understanding the global network of cell division regulation. In this article we describe a role for
YpsA, an uncharacterized protein of the SLOG superfamily of nucleotide and ligand-binding proteins, in cell division. We observed that YpsA provides protection against oxidative stress as cells lacking
show increased susceptibility to hydrogen peroxide treatment. We found that the increased expression of
leads to filamentation and disruption of the assembly of FtsZ, the tubulin-like essential protein that marks the sites of cell division in
. We also showed that YpsA-mediated filamentation is linked to the growth rate. Using site-directed mutagenesis, we targeted several conserved residues and generated YpsA variants that are no longer able to inhibit cell division. Finally, we show that the role of YpsA is possibly conserved in Firmicutes, as overproduction of YpsA in
also impairs cell division.
ABSTRACT Although many bacterial cell division factors have been uncovered over the years, evidence from recent studies points to the existence of yet-to-be-discovered factors involved in cell ...division regulation. Thus, it is important to identify factors and conditions that regulate cell division to obtain a better understanding of this fundamental biological process. We recently reported that in the Gram-positive organisms Bacillus subtilis and Staphylococcus aureus, increased production of YpsA resulted in cell division inhibition. In this study, we isolated spontaneous suppressor mutations to uncover critical residues of YpsA and the pathways through which YpsA may exert its function. Using this technique, we were able to isolate four unique intragenic suppressor mutations in ypsA (E55D, P79L, R111P, and G132E) that rendered the mutated YpsA nontoxic upon overproduction. We also isolated an extragenic suppressor mutation in yfhS, a gene that encodes a protein of unknown function. Subsequent analysis confirmed that cells lacking yfhS were unable to undergo filamentation in response to YpsA overproduction. We also serendipitously discovered that YfhS may play a role in cell size regulation. Finally, we provide evidence showing a mechanistic link between YpsA and YfhS. IMPORTANCE Bacillus subtilis is a rod-shaped Gram-positive model organism. The factors fundamental to the maintenance of cell shape and cell division are of major interest. We show that increased expression of ypsA results in cell division inhibition and impairment of colony formation on solid medium. Colonies that do arise possess compensatory suppressor mutations. We have isolated multiple intragenic (within ypsA) mutants and an extragenic suppressor mutant. Further analysis of the extragenic suppressor mutation led to a protein of unknown function, YfhS, which appears to play a role in regulating cell size. In addition to confirming that the cell division phenotype associated with YpsA is disrupted in a yfhS-null strain, we also discovered that the cell size phenotype of the yfhS knockout mutant is abolished in a strain that also lacks ypsA. This highlights a potential mechanistic link between these two proteins; however, the underlying molecular mechanism remains to be elucidated.
Raziskovalno vprašanje (RV): Kateri so najpogostejši vzroki nastanka stresa na delovnem mestu? Kakšna so najpogostejša znamenja stresa? Kakšne so najpogostejše posledice stresa? Kako lahko ...obvladujemo stres? Namen: Namen članka je proučiti članke na temo vzrokov, znamenj, posledic ter obvladovanja stresa na delovnem mestu, ločeno za EU, ZDA in Slovenijo, ter preveriti in povzeti raziskave za različne ravni: individualno, skupinsko, vodstveno in organizacijsko raven. Namen članka je kratka predstavitev rezultatov in pregled skupnih značilnosti navedenih regij. Cilj članka je ugotoviti in predstaviti razlike oz. skupne poglede na temo vzrokov, znamenj in posledic ter obvladovanja stresa na delovnem mestu med EU, ZDA in Slovenijo. Metoda: V raziskavi je bil uporabljen integrativni pregled znanstvene in strokovne literature s področja menedžmenta delovnega stresa. Preko različnih baz (Google Scholar, dLIB) smo na podlagi ključnih besed povezanih s stresom, zdravjem oz. dobrim počutjem na delovnem mestu, poiskali primerne članke. V raziskovalno nalogo smo vključili članke mlajše od 10 let s faktorjem vpliva višjim od 1,5. za članke povezane z raziskavami za EU in ZDA. Za raziskave v Sloveniji je bil pogoj, da je bil članek objavljen v indeksiranih revijah. Pregledali smo 57 člankov. V končni pregled je bilo vključenih 19 člankov, ki so ustrezali pogojem. Podatki so bili obdelani s tematsko kvalitativno analizo. Rezultati: Najpogostejši vzrok za nastanek stresa so prekomerna delovna obremenjenost in slabi medsebojni odnosi v organizaciji, kar se zelo pogosto izkazuje v izgorelosti zaposlenih, upadanju produktivnosti, povečanju bolniških odsotnosti, povečanju delovnih nesreč ter zatekanje k zlorabi alkohola, tobaka in drog. Pri obvladovanju stresa so najbolj pogosti primarni proaktivni ukrepi, ki vključujejo redno telesno aktivnost in zdrav življenjski slog, omogočanje visoke stopnje avtonomije pri delu, razni izobraževalni in wellness programi ter socialna podpora in vzpodbujanje zdravih odnosov med zaposlenimi v organizaciji. Organizacija: Rezultati raziskave vodilnemu menedžmentu in srednjemu menedžmentu nakazujejo aktivnosti menedžmenta delovnega stresa v raziskovanih regijah ter ponujajo vpogled v aktivnosti, pristope in metode, ki dosegajo dobre rezultate. Družba: Z izvajanjem proaktivnih ukrepov pri obvladovanju delovnega stresa v organizacijah preprečujemo negativne učinke prekomerne izpostavljenosti stresu na delovnem mestu in s tem pozitivno vplivamo na zadovoljstvo pri delu, zvišujemo učinkovitost delovnih mest in preprečujemo nastanek s stresom poveznih bolezenskih obolenj, ki dokazano zmanjšujejo storilnost in povečujejo stroške zdravstvene blagajne. Originalnost: Raziskava daje neposredno primerjavo vzrokov, posledic in ukrepov pri nastanku stresa na delovnem mestu treh raziskovanih regij, ki ponujajo premih obstoječih paradigem ter podlago za oblikovanje in dopolnitev obstoječih pristopov pri obvladovanju delovnega stresa. Omejitve/nadaljnje raziskovanje: Primerjava menedžmenta delovnega stresa je bila izvedena v treh regijah (ZDA, EU in Slovenija). Za širši in celovitejši vpogled na problematiko stresa, bi bilo priporočljivo raziskavo razširiti še na območje Azije (Kitajska, Južna Koreja, Japonska).
Standardni bosanski jezik pripada četveroakcenatskom novoštokavskom sistemu, od kojeg odstupa u prisutnosti silaznih akcenata u tuđicama, složenicama, genitivu jednine i akuzativu množine pojedinih ...riječi, neprenošenju akcenta na proklitiku, skraćenicama te dvosložnom refleksu jata. S obzirom na to da je uvjet da upotrebni oblik bude i normiran zapravo precizan opis kategorija, to se u ovom radu silaznom akcentu pristupa sistemski, tj. otkrivaju se moguće kategorije u kojima se silazni akcent javlja dosljedno izvan početnog sloga. Za konačno normiranje potrebno je ove kategorije ispitati na terenu, čime se ovaj rad neće baviti.Iz dosadašnjih istraživanja kao nedovoljno opisane izdvojile su se tuđice i silazni akcent u genitivu množine i vokativu jednine pojedinih riječi. S obzirom na to da se primjeri mogu grupisati prema sufiksima gotovo bez ostatka, a polazeći od teze da sufiksi mogu određivati akcenatsku sliku riječi, kategorije tuđica i riječi koje u genitivu množine i/li vokativu jednine imaju ili mogu imati silazni akcenat izvan početnog sloga kategorizirane su dakle prema sufiksima, koji su detaljno pobrojani. Korpus su činili opći rječnici bosanskog jezika, pa su date napomene i o trenutnom normativnom statusu pojedinih kategorija, od kojih su neke i normirane. Istraživanje je iznjedrilo i opći zaključak, a to je da se u bosanskom jeziku silazni akcenti izvan prvog sloga javljaju samo u trosložnim i višesložnim riječima.
The standard Bosnian language has a four-accent New Shtokavian system, from which it deviates in the presence of descending accents in some borrowings, compounds, genitive plural and vocative singular of some nouns, non-shifted accents onto proclitics, abbreviation and two-syllable reflexes of yat. Given that the condition for the common speech to be standardized is a precise description of its categories, in this paper, the approach to the falling accent is systemic, ie. the possible categories where the falling accent occurs consistently outside the initial syllable are discovered. For the final standardization, it is necessary to examine these categories in speech, which this paper will not be covering.From previous research borrowings and the falling accent in the genitive plural and the vocative singular of individual words have been singled out as insufficiently described. Considering that the examples can be grouped according to suffixes almost without remainder, and basing off of the thesis that suffixes can determine the accent of words, the borrowings and words that in the genitive plural and / or the vocative singular have or may have a falling accent outside the initial syllable are therefore categorized according to the suffixes, which are listed in detail. The corpus consists of general dictionaries of the Bosnian language, so notes are given on the current normative status of certain categories, some of which are standardized. The research also gave rise to a general conclusion, which is that, in the Bosnian language, falling accents outside the first syllable appear only in three- and multi-syllable words.
Bacillus subtilis
is a rod-shaped Gram-positive model organism. The factors fundamental to the maintenance of cell shape and cell division are of major interest. We show that increased expression of
...ypsA
results in cell division inhibition and impairment of colony formation on solid medium. Colonies that do arise possess compensatory suppressor mutations. We have isolated multiple intragenic (within
ypsA
) mutants and an extragenic suppressor mutant. Further analysis of the extragenic suppressor mutation led to a protein of unknown function, YfhS, which appears to play a role in regulating cell size. In addition to confirming that the cell division phenotype associated with YpsA is disrupted in a
yfhS
-null strain, we also discovered that the cell size phenotype of the
yfhS
knockout mutant is abolished in a strain that also lacks
ypsA
. This highlights a potential mechanistic link between these two proteins; however, the underlying molecular mechanism remains to be elucidated.
ABSTRACT
Although many bacterial cell division factors have been uncovered over the years, evidence from recent studies points to the existence of yet-to-be-discovered factors involved in cell division regulation. Thus, it is important to identify factors and conditions that regulate cell division to obtain a better understanding of this fundamental biological process. We recently reported that in the Gram-positive organisms
Bacillus subtilis
and
Staphylococcus aureus
, increased production of YpsA resulted in cell division inhibition. In this study, we isolated spontaneous suppressor mutations to uncover critical residues of YpsA and the pathways through which YpsA may exert its function. Using this technique, we were able to isolate four unique intragenic suppressor mutations in
ypsA
(E55D, P79L, R111P, and G132E) that rendered the mutated YpsA nontoxic upon overproduction. We also isolated an extragenic suppressor mutation in
yfhS
, a gene that encodes a protein of unknown function. Subsequent analysis confirmed that cells lacking
yfhS
were unable to undergo filamentation in response to YpsA overproduction. We also serendipitously discovered that YfhS may play a role in cell size regulation. Finally, we provide evidence showing a mechanistic link between YpsA and YfhS.
IMPORTANCE
Bacillus subtilis
is a rod-shaped Gram-positive model organism. The factors fundamental to the maintenance of cell shape and cell division are of major interest. We show that increased expression of
ypsA
results in cell division inhibition and impairment of colony formation on solid medium. Colonies that do arise possess compensatory suppressor mutations. We have isolated multiple intragenic (within
ypsA
) mutants and an extragenic suppressor mutant. Further analysis of the extragenic suppressor mutation led to a protein of unknown function, YfhS, which appears to play a role in regulating cell size. In addition to confirming that the cell division phenotype associated with YpsA is disrupted in a
yfhS
-null strain, we also discovered that the cell size phenotype of the
yfhS
knockout mutant is abolished in a strain that also lacks
ypsA
. This highlights a potential mechanistic link between these two proteins; however, the underlying molecular mechanism remains to be elucidated.
V razvitih družbah se prebivalstvo vse bolj stara, kar bo eden (naj)večjih ekonomskih in socialnih izzivov v prihodnosti. V Sloveniji naj bi bilo po predvidevanjih do leta 2060 30 odstotkov ...prebivalstva starejšega od 65 let, zato se utemeljeno postavlja vprašanje, kakšen je življenjski slog starejših in kako lahko v teh letih nanj še vplivamo. Nekateri starejši se iz različnih vzrokov odločijo, da bodo starost preživeli v domu za starejše. V prispevku so predstavljeni rezultati raziskave o življenjskem slogu starejših v domovih za starejše. Izvedli smo jo na vzorcu 390 starejših v domovih za starejše v Pomurju v obdobju februar– maj 2015. Uporabljeni sta bili deskriptivna analiza in kavzalno neeksperimentalna metoda empiričnega pedagoškega raziskovanja. Iz rezultatov raziskave izhaja, da na življenjski slog v domovih za starejše bistveno vplivajo socialno-ekonomski položaj, spol, status, starost in leta prebivanja v domu.
With the increasing use of object-oriented methods in new software development, there is a growing need to both document and improve current practice in object-oriented design and development. In ...response to this need, a number of researchers have developed various metrics for object-oriented systems as proposed aids to the management of these systems. In this research, an analysis of a set of metrics proposed by Chidamber and Kemerer (1994) is performed in order to assess their usefulness for practising managers. First, an informal introduction to the metrics is provided by way of an extended example of their managerial use. Second, exploratory analyses of empirical data relating the metrics to productivity, rework effort and design effort on three commercial object-oriented systems are provided. The empirical results suggest that the metrics provide significant explanatory power for variations in these economic variables, over and above that provided by traditional measures, such as size in lines of code, and after controlling for the effects of individual developers.
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