Details

Autor(en) / Beteiligte

• Upadhyay, Srijana
• Xu, Xinping
• Lowry, David
• Jackson, Jennifer C.
• Roberson, Robert W.
• Lin, Xiaorong

Titel

Subcellular Compartmentalization and Trafficking of the Biosynthetic Machinery for Fungal Melanin

Ist Teil von

• Cell reports (Cambridge), 2016-03, Vol.14 (11), p.2511-2518

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2016

Quelle

Elektronische Zeitschriftenbibliothek (Open access)

Beschreibungen/Notizen

• Protection by melanin depends on its subcellular location. Although most filamentous fungi synthesize melanin via a polyketide synthase pathway, where and how melanin biosynthesis occurs and how it is deposited as extracellular granules remain elusive. Using a forward genetic screen in the pathogen Aspergillus fumigatus, we find that mutations in an endosomal sorting nexin abolish melanin cell-wall deposition. We find that all enzymes involved in the early steps of melanin biosynthesis are recruited to endosomes through a non-conventional secretory pathway. In contrast, late melanin enzymes accumulate in the cell wall. Such subcellular compartmentalization of the melanin biosynthetic machinery occurs in both A. fumigatus and A. nidulans. Thus, fungal melanin biosynthesis appears to be initiated in endosomes with exocytosis leading to melanin extracellular deposition, much like the synthesis and trafficking of mammalian melanin in endosomally derived melanosomes. [Display omitted] •Endosomal trafficking is critical for melanization in fungi•There is stage-specific subcellular localization of the melanin biosynthetic enzymes•Early melanin enzymes have no secretion signal and are atypical secretory proteins•There is a unified cellular principle for melanogenesis in mammals and fungi Upadhyay et al. discovered that fungal melanin biosynthetic machinery is recruited to endosomes, although it is composed of largely atypical secretory proteins. Compartmentalization and trafficking through the endosomal system might be important cellular principles governing fungal secondary metabolism.