TY - JOUR
T1 - The cytoplasmic microtubule array in Neurospora crassa depends on microtubule-organizing centers at spindle pole bodies and microtubule +end-depending pseudo-MTOCs at septa
AU - Ramírez-Cota, Rosa
AU - Espino-Vazquez, Astrid N.
AU - Rodriguez-Vega, Tonacy C.
AU - Macias-Díaz, Rocío E.
AU - Callejas-Negrete, Olga A.
AU - Freitag, Michael
AU - Fischer, Reinhard
AU - Roberson, Robert W.
AU - Mouriño-Pérez, Rosa R.
N1 - Funding Information:
We thank CONACyT and the DFG for the financial support of this work (CONACyT-DFG-2016-277981-RRMP and DFG Fi 459/20-1 (RF)) also for a postdoctoral fellowship grant for RMRC from CONACYT. We are grateful to Dr. Xiaolei Gao at KIT. We thank Lanelle R. Connolly for lab assistance at OSU. Thanks to Dr. Robert Winkler for the advice in the analysis of proteins identified in the Co-IP assays. We acknowledge the Fungal Genetics Stock Center (FGSC, Kansas City, MO) for strains. Thanks to the National Laboratory of Advanced Microscopy of CICESE (LNMA-CICESE) for the support for confocal microscopy observations.
Funding Information:
We thank CONACyT and the DFG for the financial support of this work (CONACyT-DFG-2016-277981-RRMP and DFG Fi 459/20-1 (RF)) also for a postdoctoral fellowship grant for RMRC from CONACYT. We are grateful to Dr. Xiaolei Gao at KIT. We thank Lanelle R. Connolly for lab assistance at OSU. Thanks to Dr. Robert Winkler for the advice in the analysis of proteins identified in the Co-IP assays. We acknowledge the Fungal Genetics Stock Center (FGSC, Kansas City, MO) for strains. Thanks to the National Laboratory of Advanced Microscopy of CICESE (LNMA-CICESE) for the support for confocal microscopy observations.
Publisher Copyright:
© 2022 Elsevier Inc.
PY - 2022/9
Y1 - 2022/9
N2 - γ-Tubulin ring complexes (γ-TuRC) mediate nucleation and anchorage of microtubules (MTs) to microtubule organizing centers (MTOCs). In fungi, the spindle pole body (SPB) is the functional equivalent of the centrosome, which is the main MTOC. In addition, non-centrosomal MTOCs (ncMTOCs) contribute to MT formation in some fungi like Schizosaccharomyces pombe and Aspergillus nidulans. In A. nidulans, MTOCs are anchored at septa (sMTOC) and share components of the outer plaque of the SPB. Here we show that the Neurospora crassa SPB is embedded in the nuclear envelope, with the γ-TuRC targeting proteins PCP-1Pcp1/PcpA located at the inner plaque and APS-2Mto1/ApsB located at the outer plaque of the SPB. PCP-1 was a specific component of nuclear MTOCs, while APS-2 was also present at the septal pore. Although γ-tubulin was only detected at the nucleus, spontaneous MT nucleation occurred in the apical and subapical cytoplasm during recovery from benomyl-induced MT depolymerization experiments. There was no evidence for MT nucleation at septa. However, without benomyl treatment MT plus-ends were organized in the septal pore through MTB-3EB1. Those septal MT plus ends polymerized MTs from septa in interphase cells Thus we conclude that the SPB is the only MT nucleation site in N. crassa, but the septal pore aids the MT network arrangement through the anchorage of the MT plus-ends through a pseudo-MTOC.
AB - γ-Tubulin ring complexes (γ-TuRC) mediate nucleation and anchorage of microtubules (MTs) to microtubule organizing centers (MTOCs). In fungi, the spindle pole body (SPB) is the functional equivalent of the centrosome, which is the main MTOC. In addition, non-centrosomal MTOCs (ncMTOCs) contribute to MT formation in some fungi like Schizosaccharomyces pombe and Aspergillus nidulans. In A. nidulans, MTOCs are anchored at septa (sMTOC) and share components of the outer plaque of the SPB. Here we show that the Neurospora crassa SPB is embedded in the nuclear envelope, with the γ-TuRC targeting proteins PCP-1Pcp1/PcpA located at the inner plaque and APS-2Mto1/ApsB located at the outer plaque of the SPB. PCP-1 was a specific component of nuclear MTOCs, while APS-2 was also present at the septal pore. Although γ-tubulin was only detected at the nucleus, spontaneous MT nucleation occurred in the apical and subapical cytoplasm during recovery from benomyl-induced MT depolymerization experiments. There was no evidence for MT nucleation at septa. However, without benomyl treatment MT plus-ends were organized in the septal pore through MTB-3EB1. Those septal MT plus ends polymerized MTs from septa in interphase cells Thus we conclude that the SPB is the only MT nucleation site in N. crassa, but the septal pore aids the MT network arrangement through the anchorage of the MT plus-ends through a pseudo-MTOC.
KW - Aps-2
KW - MTB-3
KW - MTOCs
KW - Microtubules
KW - Neurospora crassa
KW - PCP-1
KW - SPA-18
KW - SPA10
KW - Spindle pole bodies
KW - γ-Tubulin
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U2 - 10.1016/j.fgb.2022.103729
DO - 10.1016/j.fgb.2022.103729
M3 - Article
C2 - 35944835
AN - SCOPUS:85136100005
SN - 1087-1845
VL - 162
JO - Fungal Genetics and Biology
JF - Fungal Genetics and Biology
M1 - 103729
ER -