Calmodulin concentrates at the apex of growing hyphae and localizes to the Spitzenkörper in Aspergillus nidulans

Wang, G.; Lü, Ling; Zhang, C.-Y.; Singapuri, Anil; Yuan, Sheng

doi:10.1007/s00709-006-0181-3

Cited by 26 publications

(21 citation statements)

References 40 publications

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“…MM, YAG, YG (YAG without agar), YUU, YUUK, MMGPR, and MMGTPR (MMGPR with 100 mM threonine) media have been described in previous works (38)(39)(40). Growth conditions, crosses, and induction conditions for alcA(p)-driven expression were the same as those described previously (41). Expression of tagged genes under the control of the alcA promoter was regulated by different carbon sources, with repression on glucose, derepression on glycerol, and induction on threonine.…”

Section: Methodsmentioning

confidence: 99%

Protein Phosphatase 2A (PP2A) Regulatory Subunits ParA and PabA Orchestrate Septation and Conidiation and Are Essential for PP2A Activity in Aspergillus nidulans

et al. 2014

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In recent decades, tremendous progress has been made in understanding serine/threonine protein phosphatase-dependent pathways, which are involved in the regulation of numerous processes, including secretion, cell motility, cell cycle, gene transcription, and cell metabolism (1-7). Serine/threonine phosphorylation, which is regulated by many kinases, can be reversed by a few phosphatases that are targeted to substrates via dozens of regulatory subunits (7,8). Currently, serine/threonine protein phosphatases (PPs) are grouped into two structurally distinct families: the PPP family (PP1, PP2A, and PP2B) and the PPM family (PP2C and pyruvate dehydrogenase phosphatase) (9). The PP2A heterotrimeric protein complex, which consists of a cascade of three subunits, namely, a catalytic subunit (C) and a structural subunit (A) associated with a third, hypothetically competitive and variable regulatory subunit (B), represents a highly conserved eukaryotic signal transduction system that is present in many organisms, from yeasts to humans. The activity of PP2A, along with its subcellular localization, is determined by B-family subunits (10-14). In mammals, PP2A is a major intracellular protein phosphatase that regulates multiple aspects of cell growth and metabolism (15). Therefore, PP2A is one of a few serine/threonine-specific phosphatases in the cell, and its complex structure and regulation system guarantee its various functions. The ability of this widely distributed heterotrimeric enzyme to function on a diverse array of substrates is largely controlled by the nature of its regulatory Bfamily subunits. Thus, multiple isoforms of the B-family regulatory subunit have been isolated from different organisms and grouped into three classes (B, B=, and BЉ) based on their structural similarities (16,17). The structural variations between these families support the hypothesis that the B-family regulatory subunit controls enzyme activity and specificity, such that different activities of PP2A and subcellular localization are determined by Bfamily regulatory subunits. However, one challenge we face is the potential for redundancy in the regulatory subunits' function of assigning PP2A function in mammals (18)(19)(20). Therefore, it is difficult to approach the function of PP2A globally by knocking out one of the regulatory subunits. In contrast, simple eukaryotic organisms, such as Saccharomyces cerevisiae (budding yeast) and Schizosaccharomyces pombe (fission yeast), which contain only a few isoforms of B-family regulatory subunits, are excellent model systems for studying how B-family regulatory subunits function in regulating PP2A activity. In fission yeast, there is only one B subunit of PP2A-Pab1 and two of the B=-encoding genes (par1 and par2) (21-24). Moreover, mutational studies in fission yeast have demonstrated that B regulatory subunits play crucial roles during the processes of cytokinesis, cell morphogenesis, and cell wall synthesis (25,26). Similarly, in budding yeast, studies have shown that the B class has only one ...

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Section: Methodsmentioning

confidence: 99%

Protein Phosphatase 2A (PP2A) Regulatory Subunits ParA and PabA Orchestrate Septation and Conidiation and Are Essential for PP2A Activity in Aspergillus nidulans

et al. 2014

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“…For solid media, 2 % agar was added. Growth conditions, crosses and induction conditions for alcA(p)-driven expression were as previously described (Wang et al, 2006). Transformation was done according to a method described elsewhere (May, 1989;Osmani et al, 1988).…”

Section: Methodsmentioning

confidence: 99%

The important role of actinin-like protein (AcnA) in cytokinesis and apical dominance of hyphal cells in Aspergillus nidulans

Wang

et al. 2009

Microbiology

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The actin cytoskeleton is involved in many processes in eukaryotic cells, including interaction with a wide variety of actin-binding proteins such as the actin-capping proteins, the actin filament nucleators and the actin cross-linking proteins. Here, we report the identification and characterization of an actinin-like protein (AcnA) from the filamentous fungus Aspergillus nidulans. Not only did the depletion of AcnA by alcA(p) promoter repression or the deletion of AcnA result in explicit abnormalities in septation and conidiation, but also the acnA mutants induced a loss of apical dominance in cells with dichotomous branching, in which a new branch was formed by splitting the existing tip in two. Consequently, the colony showed flabellate edges. Moreover, we found that the localization of the GFP-AcnA fusion was quite dynamic. In the isotropic expansion phase of the germinated spore, GFP-AcnA was organized as cortical patches with cables lining the cell wall. Subsequently, GFP-AcnA was localized to the actively growing hyphal tips and to the sites of septation in the form of combined double contractile rings. Our data suggest that AcnA plays an important role in cytokinesis and apical dominance of hyphal cells, possibly via actin-dependent polarization maintenance and medial ring establishment in A. nidulans. This is the first report, to our knowledge, of the function of an actinin-like protein in filamentous fungi.

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“…In fungi, CaM is required for hyphal growth, morphogenesis, germination, and penetration into plant tissue (Ahn and Suh 2007;Ahn et al 2003;Sato et al 2004;Wang et al 2006). In our previous study, we found that CaM gene expression is regulated in parallel with genes encoding most isozymes of LiP and MnP in P. chrysosporium (Minami et al 2007(Minami et al , 2009.…”

Section: Introductionmentioning

confidence: 99%

Effects of calmodulin on expression of lignin-modifying enzymes in Pleurotus ostreatus

et al. 2014

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Previously, we suppressed the expression of genes encoding isozymes of lignin peroxidase (LiP) and manganese peroxidase (MnP) using a calmodulin (CaM) inhibitor, W7, in the white-rot fungus Phanerochaete chrysosporium; this suggested that CaM positively regulates their expression. Here, we studied the role of CaM in another white-rot fungus, Pleurotus ostreatus, which produces MnP and versatile peroxidase (VP), but not LiP. W7 upregulated Mn(2+)-dependent oxidation of guaiacol, suggesting that CaM negatively regulates the production of the enzymes. Suppression of CaM in P. ostreatus using RNAi also led to upregulation of enzyme activity, whereas overexpression of CaM in P. ostreatus caused downregulation. Real-time RT-PCR showed that MnP1-6 and VP3 levels in the CaM-knockdown strain were higher than those in the wild-type strain, while MnP-5 and -6 and VP1 and 2 levels in the CaM-overexpressing strain were lower than in the wild type. Moreover, we also found that another ligninolytic enzyme, laccase, which is not produced by P. chrysosporium, was negatively regulated by CaM in P. ostreatus similar to MnP and VP. Although overexpression of CaM did not reduce the ability of P. ostreatus to digest beech wood powder, the percentage of lignin remaining in the digest was slightly higher than in the wild-type strain digest.

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Calmodulin concentrates at the apex of growing hyphae and localizes to the Spitzenkörper in Aspergillus nidulans

Cited by 26 publications

References 40 publications

Protein Phosphatase 2A (PP2A) Regulatory Subunits ParA and PabA Orchestrate Septation and Conidiation and Are Essential for PP2A Activity in Aspergillus nidulans

Protein Phosphatase 2A (PP2A) Regulatory Subunits ParA and PabA Orchestrate Septation and Conidiation and Are Essential for PP2A Activity in Aspergillus nidulans

The important role of actinin-like protein (AcnA) in cytokinesis and apical dominance of hyphal cells in Aspergillus nidulans

Effects of calmodulin on expression of lignin-modifying enzymes in Pleurotus ostreatus

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