Komunikace mezi buňkami mnohobuněčného organismu je nezbytná k zajištění přežití organismu, správné funkce tkání a orgánů, tvorby energie, růstu a vývoje. Bílkoviny sekretované z buněk jsou hlavními molekulami, které zprostředkovávají mezibuněčnou komunikaci na malé i velké vzdálenosti. Většina sekretovaných bílkovin je z buněk uvolňována cestou přes endoplasmatické retikulum a Golgiho aparát. Vývoj nových laboratorních technik pro studium sekretovaných bílkovin umožnil v posledním desetiletí studovat a popsat sekreci mnoha typů buněk., Communication among cells in a multicellular organism is fundamental for the correct functioning of organs and tissues, energy production, growth and development, to assure survival and reproduction of the organism. Proteins secreted by cells are principal molecules for intercellular communication at both short and long distances. Most of the secreted proteins are released through the endoplasmic reticulum – the Golgi pathway. The significant development of analytical techniques for detection of secreted proteins in the last 10 years has enabled us to explore the secretion of various cell types., and Helena Kupcová Skalníková.
Ohromujúci vývoj laserových optických metód umožnil širokú plejádu manipulácií s objektmi pomocou svetelného lúča a ďalej podnietil vývoj experimentálnych postupov umožňujúcich zachytiť subpikonewtonovské sily medzi molekulami. Aplikácia optického silomera pri štúdiu vlastností biomakromolekúl nám pomáha chápať fyzikálne princípy mechanickej funkcie týchto komplexných nanometrových objektov., The extensive development of laser technology has enabled a large variety of object manipulations with light. This has initiated the development of experimental assays for the detection of sub piconewton forces between molecules. The application of an optical force meter for the study of bio-macromolecules reveals elementary physical principles of the mechanical function of these complex nano sized objects., Gabriel Žoldák., and Obsahuje bibliografické odkazy
Prolonged agonist stimulation results in specific transfer of activated Gα subunits of Gqα/G11α family from particulate membrane fraction to soluble (cytosol) cell fraction isolated as 250 000 x g supernatant. In this study, we have used 2D electrophoresis for more defined resolution of Gα subunits of Gqα/G11α family and followed the time course of solubilization effect. The small signal of soluble G proteins was already detected in control, hormone-unexposed cells. Hormone stimulation resulted in a slow but continuous increase of both intensity and number of immunoreactive signals/spots of these G proteins (10, 30, 60, 120 and 240 min). At longer times of agonist exposure (>2 hours), a marked increase of Gqα/G11α proteins was detected. The maximal level of soluble Gqα/G11α proteins was reached after 16 hours of continuous agonist exposure. At this time interval, eight individual immunoreactive signals of Gqα/G1 α proteins could be resolved. The relative proportion among these spots was 15:42:10:11:7:7:2:5. Solubilization of this class of Gα proteins was thus observed after prolonged agonist stimulation only, induced by ultra high concentration of hormone and in cells expressing a large number of GPCRs. Our data therefore rather indicate tight/persisting binding of Gqα/G11α proteins to the membrane., D. Durchánková, J. Novotný, P. Svoboda., and Obsahuje bibliografii a bibliografické odkazy