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1

Białka opiekuńcze - "molekularne przyzwoitki" w fałdowaniu białek

100%

Bregier C., Fabczak H., Fabczak S.

Kosmos

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2007

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vol. 56

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issue 3-4

409-419

EN

Proteins must be folded into their correct three-dimensional conformation in order to attain biological function. Conversely, protein aggregation and misfolding are primary contributors to many devastating "conformational" diseases. Proteins are synthesized and folded continuously. The last of these processes is greatly assisted by molecular chaperones. They are a group of structurally diverse and mechanistically distinct proteins that either promote folding or prevent the aggregation of other proteins. Proteins that can be classified as molecular chaperones can be divided into two groups: (a) ribosome-associated chaperons responsible for co-traslational folding of polypetides and (b) cytoplasmic molecular chaperones including Hsp90, Hsp70/Hsp40 and chaperonin CCT in eukaryotic cells. Prokaryotic cells posses DnaK/DnaJ system and GroEL/GroES, respectively. This review focuses on the emerging role of molecular chaperones in protein quality control in eukaryotic and prokaryotic cells.

2

Cytoszkielet i ruch komórki

100%

Fabczak H., Rędowicz M., Włoga D.

Kosmos

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2018

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vol. 67

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issue 1

13-14

3

Cytoskeleton and cell motility

100%

Fabczak H., Rędowicz M., Włoga D.

Kosmos

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2018

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vol. 67

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issue 1

15-16

4

Biogeneza rzęski pierwotnej

100%

Poprzeczko M., Joachimiak E., Włoga D., Fabczak H.

Kosmos

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2018

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vol. 67

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issue 1

179-193

PL

Rzęski pierwotne, struktury zbudowane na bazie cytoszkieletu mikrotubularnego, występują na powierzchni niemal wszystkich komórek ssaczych. Dzięki licznym receptorom błonowym, rzęski pierwotne pośredniczą w odbieraniu i przekazywaniu bodźców ze środowiska do wnętrza komórki, i tym samym odgrywają niezwykle ważną rolę w prawidłowym rozwoju i funkcjonowaniu większości tkanek i narządów. Tworzenie rzęski (ciliogeneza) to złożony, wieloetapowy i wielopoziomowo regulowany proces ściśle związany z cyklem komórkowym. Mutacje w genach kodujących białka strukturalne lub odpowiedzialne za prawidłowe funkcjonowanie rzęsek, jak również, regulujące przebieg ciliogenezy są przyczyną ich dysfunkcji, prowadzącej w efekcie do wielonarządowych chorób zwanych ciliopatiami.

EN

Cilia are highly specialized, microtubule-based protrusions, extended on cell surface in almost all mammalian cell types. They function as cell antennae that receive and transmit signals from the environment to the cell body. Cilia formation, so-called ciliogenesis is strictly controlled at multiple levels by a number of proteins, and correlated with the cell cycle progression. Cilia dysfunctions cause a wide range of human diseases, called ciliopathies. Moreover, ciliary defects may lead to obesity and cancer. In this article, we summarize current knowledge concerning cilia function and structure, regulation of ciliogenesis, and the most important signaling pathways and diseases affected by cilia dysfunction.

5

Dimer αγ białka G - cząsteczka sygnałowa

100%

Fabczak H., Sobierajska K., Fabczak S.

Kosmos

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2004

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vol. 53

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issue 3-4

355-372

EN

Summary The extracellular signals received by receptors with seven membrane-spanning regions that activate the G proteins, are routed to several distinct intracellular pathways. The G proteins consist of two functional units, Gα subunit, that binds guanine nucleotides and Gβγ dimer that functions as a single unit. The regulation of signal transduction by the Gβγ complex at different protein interfaces: subunit - subunit, receptor - G protein, and Gβγ - effector, are reviewed. Gβγ dimer regulates over twelve cellular effectors including phospholipase-β, adenyl cyclases, ion channels and G-protein coupled receptor kinases, which control a broad range of cellular processes.

6

Effects of Roscovitine on Schedule of Divisional Morphogenesis, Basal Bodies Proliferation and Cell Divisions in Tetrahymena thermophila

88%

Kaczanowska J., Kiersnowska M., Fabczak H., Kaczanowski S., Kaczanowski A.

Acta Protozoologica

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2012

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vol. 51

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issue 2

PL

During cell cycle of a ciliate Tetrahymena thermophila the divisions of micro- and macronucleus, cortical morphogenesis and cytokinesis are temporarily coordinated. Cortical morphogenesis begins with proliferation of the new ciliary basal bodies (BBs) within meridional cortical rows of ciliary BBs, and with the local proliferation of BBs, which form the new oral apparatus (OA2), positioned subequatorialy and destined for prospective posterior daughter cell (opisthe). Prior to cytokinesis, two prospective daughter cells are of equal size and show metamery of their cortical patterns. We studied effects of 20 μM roscovitine (an inhibitor of several cyclin-dependent kinases) on the cell cycle progression of T. thermophila. We showed that roscovitine delayed cell division, delayed or arrested macronuclear division and induced increase of cell size and the number of BBs in the cortical rows. The increase in the number of BBs in cortical rows induced cell elongation which was proportional to the increase in cell surface area. There was uncoupling between this BBs proliferation which is continued during prolonged cell cycle and delayed cytokinesis, what resulted in topological alteration of the respective positions of the OA2 and of the contractile vacuole pores (CVPs). In roscovitine treated cells, the new OA2 was positioned subequatorialy, but the fission zone was shifted posterior to the equatorial plane of the cell and positioned across and in the extreme cases behind of the new OA2. This resulted in the formation of a large proter and small size opisthe. The roscovitine treatment induced a formation of a plethora of phenotypes of postdividing cells. We found that irrespective of changes in divisional morphogenesis induced by roscovitine treatment, all mature BBs were associated with the cdc14-like phosphatase. Taken together all these data indicate that during cell cycle of T. thermophila the normal morphology of the daughter cells depends on the proper division of micro- and macronucleus and on temporal control of BBs proliferation along the longitudinal rows, during OA2 stomatogenesis and during selection of BBs involved in differentiation of apical BBs (couplets) and cell division.

7

Budowa rzęsek - od ultrastruktury do funkcji

88%

Urbańska P., Joachimiak E., Bazan R., Fabczak H., Włoga D.

Kosmos

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2018

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vol. 67

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issue 1

195-205

PL

Rzęski są strukturami zachowanymi w toku ewolucji, występującymi u większości Eukaryota. Ze względu na strukturę i pełnione funkcje wyróżnia się dwa typy rzęsek: nieruchome rzęski pierwotne, tworzone w fazie spoczynkowej cyklu komórkowego oraz rzęski ruchome. Rzęski pierwotne są odpowiedzialne za odbieranie i przekazywanie sygnałów ze środowiska do wnętrza komórki, natomiast rzęski ruchome umożliwiają ruch pojedynczych komórek, a w organizmach wielokomórkowych, w tym u człowieka, przemieszczanie wydzielin lub drobin wzdłuż powierzchni komórek nabłonka wyścielającego m.in. drogi oddechowe, jajowód i komory mózgowia. Szkielet obu typów rzęsek, tzw. aksomena, zbudowany jest z dziewięciu obwodowych par mikrotubul. Rzęski ruchome mają dodatkowo dwie mikrotubule centralne, które wraz z przyłączonymi do nich kompleksami białkowymi tworzą kompleks pary centralnej, oraz makrokompleksy białek przyłączone do mikrotubul obwodowych. Makrokompleksy te są rozmieszczone periodycznie wzdłuż mikrotubul obwodowych, tworząc wzór powtarzający się co 96 nm. W każdym powtórzeniu znajdują się cztery zewnętrzne ramiona dyneinowe, siedem wewnętrznych ramion dyneinowych, trzy promienie łączące, po jednym kompleksie N-DRC i MIA, oraz inne, mniejsze kompleksy. Skoordynowane działanie tych makrokompleksów jest niezbędne do prawidłowego ruchu rzęsek.

EN

Cilia are highly evolutionarily conserved structures, assembled by most of the eukaryotic cells. Because of the differences in the ultrastructure and function, cilia are divided into two categories: immotile primary cilia that function as antennae and receive signals from the environment and transmit them into the cell, and motile cilia, which enable motility of the single cell. In multicellular organisms including humans the coordinated beating of motile cilia shifts fluids or particles along the surface of the cell in the respiratory tracks, Fallopian tube or brain ventricles. Both primary and motile cilia are supported by a microtubular skeleton, the axoneme, composed of nine periph- eral microtubule doublets. Additionally, motile cilia have a pair of central microtubules with their appendages, the so-called central pair (CP) complex, and macrocomplexes that are periodically attached to the microtubules of the peripheral doublets forming a specific pattern along the microtubules that repeats every 96 nm. The 96-nm repeat contains 4 outer and 7 inner dynein arms, 3 radial spokes, a single nexin-dynein regulatory complex and a modifier of inner arms as well as other minor complexes. The coordinated action of these macrocomplexes is indispensable for proper cilia beating.

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Białka opiekuńcze - "molekularne przyzwoitki" w fałdowaniu białek

Cytoszkielet i ruch komórki

Cytoskeleton and cell motility

Biogeneza rzęski pierwotnej

Dimer αγ białka G - cząsteczka sygnałowa

Effects of Roscovitine on Schedule of Divisional Morphogenesis, Basal Bodies Proliferation and Cell Divisions in Tetrahymena thermophila

Budowa rzęsek - od ultrastruktury do funkcji