Naslov
Rapid recycling – unrevealed pathways of endosomal traveling towards cell membrane

Autori
Blagojević Zagorac, Gordana ; Mahmutefendić Lučin, Hana ; Maćešić, Senka ; LUčin, Pero

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
18. znanstvena tribina Hrvatske akademije znanosti i umjetnosti / - , 2018, 2-2

Skup
18. znanstvena tribina Hrvatske akademije znanosti i umjetnosti

Mjesto i datum
Rijeka, Hrvatska, 20.09.2018

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Domaća recenzija

Ključne riječi
endosomal recycling, MCMV, rapid recycling

Sažetak
Endocytosis is essential cellular process by which extracellular fluid (fluid phase endocytosis) and membrane proteins and their ligands (receptor mediated endocytosis) enter the cell and enable maintenance of cell homeostasis. Following endocytosis, endocytosed molecules are directed either to late endosomal route for degradation or are returned back to the plasma membrane by process called endosomal recycling. Endosomal recycling is highly regulated and highly dynamic process that involves activation of multiple Rab and Arf proteins and takes place at different endosomal levels. Endosomal system is composed of different structures that continuously undergo fusion and fission reactions, exchange and sort cargo that flows from small peripheral pre-early endosomes (pre-EEs) to large central endosomes. Traditionally, recycling route is divided into two steps ; fast recycling route that takes place at the level of early endosomes (EE) and the slow route that occurs from endosomal recycling compartment (ERC). However, some authors, by using fluorescent lipophilic dyes shown that recycling occurs very early after endocytosis and this recycling route is often called rapid recycling because it is activated 2-3 minutes after endocytosis. Rapid recycling route is mainly underestimated because most of the data about endosomal recycling was generated from studying transferrin/transferrin receptor (Tf/TfR) intracellular trafficking due to availability of a good tool for Tf labelling. However, indicator of Tf recycling is the quantification of the ligand release from the cell and the release of Tf only occurs when Tf-TfR complex reaches sufficiently acidic compartment which converts holo- into apo-Tf. Therefore, the rapid recycling was invisible to conventional assays, and only development of the new techniques like TIRFM and live microscopy enabled visualisation of rapid recycling vesicles. In our lab we analyzed intracellular trafficking of seven different cargo molecules (transferrin receptor, fully conformed and non-conformed MHC-I, CD44, cholera-toxin B subunit, ICAM1, and G-protein coupled receptor Rae-1) which use different intracellular routes. For that purpose we created multicompartment mathematical model and we developed software by which we can follow intracellular trafficking of endocytosed molecules. We have shown that all investigated molecules use rapid recycling route following endocytosis. From this data we can conclude that rapid recycling takes place constitutively and it is very important for the maintenance of cell homeostasis and should not be forgotten when analyzing cellular processes.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

POVEZANOST RADA