scholarly journals Roles of Protein Kinase A and Adenylate Cyclase in Light-Modulated Cellulase Regulation in Trichoderma reesei

2012 ◽  
Vol 78 (7) ◽  
pp. 2168-2178 ◽  
Author(s):  
André Schuster ◽  
Doris Tisch ◽  
Verena Seidl-Seiboth ◽  
Christian P. Kubicek ◽  
Monika Schmoll
Keyword(s):  
Gene Expression ◽  
Protein Kinase ◽  
Adenylate Cyclase ◽  
Protein Kinase A ◽  
Trichoderma Reesei ◽  
Cellulase Gene ◽  
Transcript Levels ◽  
Content Type ◽  
Camp Pathway ◽  
Kinase A

ABSTRACTThe cyclic AMP (cAMP) pathway represents a central signaling cascade with crucial functions in all organisms. Previous studies ofTrichoderma reesei(anamorph ofHypocrea jecorina) suggested a function of cAMP signaling in regulation of cellulase gene expression. We were therefore interested in how the crucial components of this pathway, adenylate cyclase (ACY1) and cAMP-dependent protein kinase A (PKA), would affect cellulase gene expression. We found that both ACY1 and PKA catalytic subunit 1 (PKAC1) are involved in regulation of vegetative growth but are not essential for sexual development. Interestingly, our results showed considerably increased transcript abundance of cellulase genes in darkness compared to light (light responsiveness) upon growth on lactose. This effect is strongly enhanced in mutant strains lacking PKAC1 or ACY1. Comparison to the wild type showed that ACY1 has a consistently positive effect on cellulase gene expression in light and darkness, while PKAC1 influences transcript levels of cellulase genes positively in light but negatively in darkness. A function of PKAC1 in light-modulated cellulase gene regulation is also reflected by altered complex formation within thecel6a/cbh2promoter in light and darkness and in the absence ofpkac1. Analysis of transcript levels of cellulase regulator genes indicates that the regulatory output of the cAMP pathway may be established via adjustment of XYR1 abundance. Consequently, both adenylate cyclase and protein kinase A are involved in light-modulated cellulase gene expression inT. reeseiand have a dampening effect on the light responsiveness of this process.

scholarly journals Role for Protein Kinase A in the Neurospora Circadian Clock by Regulating White Collar-IndependentfrequencyTranscription through Phosphorylation of RCM-1

2015 ◽  
Vol 35 (12) ◽  
pp. 2088-2102 ◽  
Author(s):  
Xiao Liu ◽  
Hongda Li ◽  
Qingqing Liu ◽  
Yanling Niu ◽  
Qiwen Hu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Kinase ◽  
Circadian Clock ◽  
Protein Kinase A ◽  
White Collar ◽  
Content Type ◽  
Clock Gene Expression ◽  
Kinase A

Rhythmic activation and repression of clock gene expression is essential for the eukaryotic circadian clock functions. In theNeurosporacircadian oscillator, the transcription of thefrequency(frq) gene is periodically activated by the White Collar (WC) complex and suppressed by the FRQ-FRH complex. We previously showed that there is WC-independentfrqtranscription and its repression is required for circadian gene expression. How WC-independentfrqtranscription is regulated is not known. We show here that elevated protein kinase A (PKA) activity results in WC-independentfrqtranscription and the loss of clock function. We identified RCM-1 as the protein partner of RCO-1 and an essential component of the clock through its role in suppressing WC-independentfrqtranscription. RCM-1 is a phosphoprotein and is a substrate of PKAin vivoandin vitro. Mutation of the PKA-dependent phosphorylation sites on RCM-1 results in WC-independent transcription offrqand impaired clock function. Furthermore, we showed that RCM-1 is associated with the chromatin at thefrqlocus, a process that is inhibited by PKA. Together, our results demonstrate that PKA regulatesfrqtranscription by inhibiting RCM-1 activity through RCM-1 phosphorylation.

scholarly journals Serial Analysis of Gene Expression Reveals Conserved Links between Protein Kinase A, Ribosome Biogenesis, and Phosphate Metabolism in Ustilago maydis

2005 ◽  
Vol 4 (12) ◽  
pp. 2029-2043 ◽  
Author(s):  
Luis M. Larraya ◽  
Kylie J. Boyce ◽  
Austin So ◽  
Barbara R. Steen ◽  
Steven Jones ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Ustilago Maydis ◽  
Filamentous Growth ◽  
Camp Signaling ◽  
Phosphate Metabolism ◽  
Wild Type ◽  
Transcript Levels ◽  
Kinase A

ABSTRACT The switch from budding to filamentous growth is a key aspect of invasive growth and virulence for the fungal phytopathogen Ustilago maydis. The cyclic AMP (cAMP) signaling pathway regulates dimorphism in U. maydis, as demonstrated by the phenotypes of mutants with defects in protein kinase A (PKA). Specifically, a mutant lacking the regulatory subunit of PKA encoded by the ubc1 gene displays a multiple-budded phenotype and fails to incite disease symptoms, although proliferation does occur in the plant host. A mutant with a defect in a catalytic subunit of PKA, encoded by adr1, has a constitutively filamentous phenotype and is nonpathogenic. We employed serial analysis of gene expression to examine the transcriptomes of a wild-type strain and the ubc1 and adr1 mutants to further define the role of PKA in U. maydis. The mutants displayed changes in the transcript levels for genes encoding ribosomal proteins, genes regulated by the b mating-type proteins, and genes for metabolic functions. Importantly, the ubc1 mutant displayed elevated transcript levels for genes involved in phosphate acquisition and storage, thus revealing a connection between cAMP and phosphate metabolism. Further experimentation indicated a phosphate storage defect and elevated acid phosphatase activity for the ubc1 mutant. Elevated phosphate levels in culture media also enhanced the filamentous growth of wild-type cells in response to lipids, a finding consistent with PKA regulation of morphogenesis in U. maydis. Overall, these findings extend our understanding of cAMP signaling in U. maydis and reveal a link between phosphate metabolism and morphogenesis.

scholarly journals Glucose sensing via the protein kinase A pathway in Schizosaccharomyces pombe

2005 ◽  
Vol 33 (1) ◽  
pp. 257-260 ◽  
Author(s):  
C.S. Hoffman
Keyword(s):  
Protein Kinase ◽  
Adenylate Cyclase ◽  
Schizosaccharomyces Pombe ◽  
Protein Kinase A ◽  
G Protein ◽  
Glucose Sensing ◽  
Independent Manner ◽  
Camp Phosphodiesterase ◽  
Camp Pathway ◽  
Kinase A

The fission yeast Schizosaccharomyces pombe primarily detects glucose via a cAMP-signalling pathway. Components of this pathway include the Git3 G-protein-coupled receptor and a heterotrimeric G-protein, from which the Gpa2 Gα subunit activates adenylate cyclase (Git2/Cyr1). Three additional proteins, Git1, Git7 and Git10 are required to generate a cAMP response even in a strain expressing an activated form of Gpa2, which is capable of bypassing the loss of the GPCR and Gβγ dimer. Therefore, Git1, Git7 and Git10 either act in a G-protein-independent manner or are required to stabilize or assemble a functional signalling complex. Although prior data suggested that the Cgs2 cAMP phosphodiesterase (PDE) does not regulate the cAMP response, we now have evidence that along with adenylate cyclase regulation, PDE activation is important for limiting the response to glucose. Finally, regulation of protein kinase A activation appears to involve both traditional post-translational regulation of the function of the components of the cAMP pathway and glucose-dependent transcriptional regulation of some of these cAMP pathway genes.

scholarly journals Pituitary adenylate cyclase activating polypeptide as a novel hypophysiotropic factor in fish

2000 ◽  
Vol 78 (3) ◽  
pp. 329-343 ◽  
Author(s):  
Anderson OL Wong ◽  
Wen Sheng Li ◽  
Eric KY Lee ◽  
Mei Yee Leung ◽  
Lai Yin Tse ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Adenylate Cyclase ◽  
Protein Kinase A ◽  
Anterior Pituitary ◽  
Kinase C ◽  
Pituitary Adenylate Cyclase ◽  
Pacap Receptors ◽  
Kinase A

Pituitary adenylate cyclase activating polypeptide (PACAP) is a novel member of the secretin-glucagon peptide family. In mammals, this peptide has been located in a wide range of tissues and is involved in a variety of biological functions. In lower vertebrates, especially fish, increasing evidence suggests that PACAP may function as a hypophysiotropic factor regulating pituitary hormone secretion. PACAP has been identified in the brain-pituitary axis of representative fish species. The molecular structure of fish PACAP is highly homologous to mammalian PACAP. The prepro-PACAP in fish, however, is distinct from that of mammals as it also contains the sequence of fish GHRH. In teleosts, the anterior pituitary is under direct innervation of the hypothalamus and PACAP nerve fibers have been identified in the pars distalis. Using the goldfish as a fish model, mRNA transcripts of PACAP receptors, namely the PAC1 and VPAC1 receptors, have been identified in the pituitary as well as in various brain areas. Consistent with the pituitary expression of PACAP receptors, PACAP analogs are effective in stimulating growth hormone (GH) and gonadotropin (GTH)-II secretion in the goldfish both in vivo and in vitro. The GH-releasing action of PACAP is mediated via pituitary PAC1 receptors coupled to the adenylate cyclase-cAMP-protein kinase A and phospholipase C-IP3-protein kinase C pathways. Subsequent stimulation of Ca2+ entry through voltage-sensitive Ca2+ channels followed by activation of Ca2+-calmodulin protein kinase II is likely the downstream mechanism mediating PACAP-stimulated GH release in goldfish. Although the PACAP receptor subtype(s) and the associated post-receptor signaling events responsible for PACAP-stimulated GTH-II release have not been characterized in goldfish, these findings support the hypothesis that PACAP is produced in the hypothalamus and delivered to the anterior pituitary to regulate GH and GTH-II release in fish.Key words: PACAP, VIP, PAC1 receptor, VPAC1 receptor, VPAC2 receptor, growth hormone, gonadotropin-II, cAMP, protein kinase A, protein kinase C, calcium, pituitary cells, goldfish, and teleost.

High glucose-associated osmolality promotes adipocytogenic differentiation of primary rat osteoblasts in a protein kinase A and phosphatidylinositol 3-kinase/Akt-dependent manner

Biologia ◽  
2015 ◽  
Vol 70 (10) ◽  
Author(s):  
Yu Zhang ◽  
Pu Feng ◽  
Jianhong Yang
Keyword(s):  
Gene Expression ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Real Time ◽  
High Glucose ◽  
Marker Gene ◽  
Dependent Manner ◽  
Phosphatidylinositol 3 Kinase ◽  
Marker Gene Expression ◽  
Kinase A

AbstractIncreased risk of osteoporosis in patients with diabetes mellitus may be related to hyperglycemia. However, the potential mechanisms accounting for diabetic bone disorder remain unresolved. The present study investigated the effects of high glucose-associated osmolality on differentiation of primary rat calvarial osteoblasts. Osteoblastogenic differentiation was determined by bone nodule staining for mineralization assay, enzyme-linked immunosorbent assay for type I collagen production and real-time polymerase chain reaction (PCR) for osteoblastogenic marker gene expression. Adipocytogenic differentiation was assessed by oil red O staining for lipid accumulation and real-time PCR for adipocytogenic marker gene expression. The phosphorylations of protein kinase A (PKA) and Akt were measured with or without specific inhibitors to confirm osmolality involved signalling pathways. The results showed that high glucose-associated osmolality significantly promoted adipocytogenic differentiation, manifested by increased lipid droplet formation and gene expression of adipocytogenic markers including adipocyte fatty acid binding protein (aP2), adipsin and peroxisome proliferator-activated receptor gamma (PPARγ). Meanwhile, high glucose-associated osmolality inhibited osteoblastogenic differentiation, characterized by decreased collagen I protein production and cell mineralization, as well as gene expression of osteoblastogenic markers including collagen I, osteocalcin and runt-related transcription factor 2 (Runx2). More importantly, we demonstrated for the first time that high glucose-associated osmolality induced adipocytogenic differentiation and suppressed osteoblastogenic differentiation in a PKA and phosphatidylinositol 3-kinase (PI3K)/Akt-dependent manner. These results indicated that osmolality was involved in high glucose-induced osteoblast trans-differentiation into adipocyte-like cell and suppression of cellular osmolality could provide novel therapeutic approach for diabetic osteopenia.

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