Naslov
Endocytosis of full and empty Ld molecules in nonpolarized cells

Autori
Mahmutefendić, Hana ; Kučić, Natalia ; Lučin, Pero

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

Izvornik
American Journal of Reproductive Immunology / Gleicher, Norbert - Kopenhagen : Munksgaard, 2001, 60-61

Skup
VIII International Congress of Reproductive Immunology

Mjesto i datum
Opatija, Hrvatska, 02.07.2001. - 06.07.2001

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
-

Sažetak
Problem To characterize the endocytic pathway of MHC class I molecules, we have studied the expression of Ld molecules on nonpolarized murine P815 cells. These molecules reach the cell surface in the full conformation, composed of properly folded heavy chain, beta2 -microglobulin (beta2m) and peptide, and the empty, which is represented either by non-conformed heavy chains or hetrodimer of weakly associated non-conformed heavy chain and beta2m. Methods of Study In order to investigate the mechanism a palette of inhibitors of the endocytosis and vesicular transport was used. Cycloheximide, an inhibitor of protein synthesis, induced spontaneous endocytosis of Ld molecules and their disappearance from the cell surface or degradation was followed by flow cytometry and Western blott. Results As inhibitors of clathrine endocytosis, chlorpromazine (CP) and peroxovanadate, did not influence the internalization of full and empty Ld molecules. Filipin and nystatin, inhibitors of the caveolar endocytosis, prevented downregulation of empty, but not of full Ld molecules. NH4Cl, prevented the degradation of a majority of empty Ld. As inhibitors of the recycling pathway, CP and bafilomycin A1 caused surface decrease, but intracellular increase of full Ld. Conclusions From these results we can conclude that both full and empty Ld molecules are internalized by caveolar endocytosis. A majority of full Ld molecules are recycled back to the cell surface, and only small amount is degraded. In contrast, one part of the empty Ld is recycled directly to the cell surface, and probably, a major part is transformed in early endosomes into full Ld molecules and transported back to the cell surface. Supported by grant No. 062006 from the Ministry of Science and Technology, Republic of Croatia.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

POVEZANOST RADA