The Golgi apparatus: insights from filamentous fungi

Abstract

Cargo passage through the Golgi, albeit an undoubtedly essential cellular function, is a mechanistically unresolved and much debated process. Although the main molecular players are conserved, diversification of the Golgi among different eukaryotic lineages is providing us with tools to resolve standing controversies. During the past decade the Golgi apparatus of model filamentous fungi, mainly Aspergillus nidulans, has been intensively studied. Here an overview of the most important findings in the field is provided. Golgi architecture and dynamics, as well as the novel cell biology tools that were developed in filamentous fungi in these studies, are addressed. An emphasis is placed on the central role the Golgi has as a crossroads in the endocytic and secretory-traffic pathways in hyphae. Finally the major advances that the A. nidulans Golgi biology has yielded so far regarding our understanding of key Golgi regulators, such as the Rab GTPases RabC Rab6 and RabE Rab11 , the oligomeric transport protein particle, TRAPPII, and the Golgi guanine nucleotide exchange factors of Arf1, GeaA GBF1/Gea1 and HypB BIG/Sec7 , are highlighted.

On‐site secretory vesicle delivery drives filamentous growth in the fungal pathogenCandida albicans

“…We hypothesised that these elongated membranes could be part of the ER or the Golgi, as these compartments were previously observed in C. albicans filamentous cells using fluorescent microscopy (Ghugtyal et al, 2015;Rida et al, 2006). Examination of the 3D membrane organisation in (Preuss, Mulholland, Franzusoff, Segev, & Botstein, 1992), and also resembles Golgi in other filamentous fungi (Pantazopoulou, 2016). It should be noted that there appears to be a continuous transition between these two membrane domains.…”

Clathrin localization and dynamics in Aspergillus nidulans

“…B) (Löpez‐Franco and Bracker, ; Araujo‐Palomares et al ., ). The ClaH‐GFP exclusion zone seen in growing cells was similar to that seen with late Golgi equivalents in A. nidulans (Pantazopoulou and Peñalva, ; Pantazopoulou et al ., ; Pinar et al ., ; Pantazopoulou, ).…”

“…Third, the endocytic collar that just precedes the hyphal tip is a uniquely fungal structure that is important for the maintenance of somatic fungal growth, and little is known about endocytic protein dynamics there (Araujo‐Bazán et al ., ; Lee et al ., ; Taheri‐Talesh et al ., ; Upadhyay and Shaw, ; Delgado‐Álvarez et al ., ; Echauri‐Espinosa et al ., ; Schultzhaus and Shaw, ; Schultzhaus et al ., ). Finally, membrane progression through Golgi is coupled to polarized growth and is easily visualized in filamentous fungi, allowing for the examination of any clathrin structures that might be found at this organelle (Bracker, ; Howard, ; Dargent et al ., ; Cole et al ., ; Hohmann‐Marriott et al ., ; Bowman et al ., ; Pantazopoulou and Peñalva, ; Harris, ; Pinar et al ., ; Pantazopoulou et al ., ; Sánchez‐León et al ., ; Kim et al ., ; Pantazopoulou, ; Riquelme et al ., ).…”

Genetic dissection of the secretory route followed by a fungal extracellular glycosyl hydrolase

“…To demonstrate that sarA8 causes a major block in the exit of COPII traffic from the ER (see scheme in Fig. A), we used the integral membrane proteins and early Golgi residents RerA Rer1 and SedV Sed5 [see (Pantazopoulou, ) for a review]. RerA Rer1 is a cargo receptor that cycles continuously between the ER and the Golgi (Pinar et al, ; Sato et al, )(Fig.…”

“…The biogenesis of Golgi cisternae involves the coalescence of ER‐derived vesicles, mediated by the GTPase RAB1 (RabO RAB1 ) and syntaxin‐5 (SedV Sed5 in A. nidulans ) mentioned above (Pantazopoulou, ). sedV R258G and rabO A136D are ts mutations that inactivate these regulators at 37°C and higher (Pinar et al, ).…”