The transportosome system as a model for the retrotransport of soluble proteins

MAZAIRA GI,; ERLEJMAN AG; ZGAJNAR NR; PIWIEN-PILIPUK G; GALIGNIANA MD

MOLECULAR AND CELLULAR ENDOCRINOLOGY.

ELSEVIER IRELAND LTD

Lugar: Amsterdam; Año: 2022

0303-7207

The evolutionary pressure led to the compartmentalization of the cell work, an architecture that implies the transport of proteins to their sites of action in the cell. Sometimes, this is achieved stochastically by passive diffusion; at other times, an active transport system is required. Very often, the disruption of such transport mechanism constitutes the molecular reason for several diseases. The classic model of action for the glucocorticoid receptor sustains that its associated chaperone, HSP90, favours the cytoplasmic retention of the unliganded receptor, whereas the binding of steroid triggers the dissociation of HSP90, which allows the accumulation of the receptor in the nucleus. In recent years, it was described a molecular machinery named transportosome, which is responsible for the active retrotransport of steroid receptors. The elemental hub unit of this heterocomplex includes a dimer of HSP90 and the immunophilin FKBP52, which has the capability to interact with dynein/dynactin motor proteins. Subsequent findings demonstrated that the transportosome is also responsible for the transport of other soluble factors. In this article, we discuss the relevance of this transport machinery in health and disease