Hansenula polymorpha: An attractive model organism for molecular studies of peroxisome biogenesis and function

AbstractWe analyzed all four Pex23 family proteins of the yeast Hansenula polymorpha, which localize to the ER. Of these Pex24 and Pex32, but not Pex23 and Pex29, accumulate at peroxisome-ER contacts, where they are important for normal peroxisome biogenesis and proliferation and contribute to organelle positioning and segregation.Upon deletion of PEX24 and PEX32 - and to a lesser extent of PEX23 and PEX29 - peroxisome-ER contacts are disrupted, concomitant with peroxisomal defects. These defects are suppressed upon introduction of an artificial peroxisome-ER tether.Accumulation of Pex32 at peroxisomes-ER contacts is lost in the absence of the peroxisomal membrane protein Pex11. At the same time peroxisome-ER contacts are disrupted, indicating that Pex11 contributes to Pex32-dependent peroxisome-ER contact formation.Summarizing, our data indicate that H. polymorpha Pex24 and Pex32 are tethers at peroxisome-ER contacts that are important for normal peroxisome biogenesis and dynamics.SummaryTwo Hansenula polymorpha ER proteins, Pex24 and Pex32, are tethers at peroxisome-ER contacts and function together with the peroxisomal protein Pex11. Their absence disturbs these contacts leading to multiple peroxisomal defects, which can be restored by an artificial tether.

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Peroxisome Biogenesis and Function

The Arabidopsis Book ◽

10.1199/tab.0123 ◽

2009 ◽

Vol 7 ◽

pp. e0123 ◽

Cited By ~ 56

Author(s):

Navneet Kaur ◽

Sigrun Reumann ◽

Jianping Hu

Keyword(s):

Peroxisome Biogenesis ◽

And Function

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FOXP2 exhibits projection neuron class specific expression, but is not required for multiple aspects of cortical histogenesis

eLife ◽

10.7554/elife.42012 ◽

2019 ◽

Vol 8 ◽

Cited By ~ 6

Author(s):

Ryan J Kast ◽

Alexandra L Lanjewar ◽

Colton D Smith ◽

Pat Levitt

Keyword(s):

Expression Patterns ◽

Projection Neuron ◽

Specific Expression ◽

Neuron Populations ◽

Mouse Cortex ◽

Molecular Studies ◽

Multiple Species ◽

Molecular Phenotypes ◽

And Function

The expression patterns of the transcription factor FOXP2 in the developing mammalian forebrain have been described, and some studies have tested the role of this protein in the development and function of specific forebrain circuits by diverse methods and in multiple species. Clinically, mutations in FOXP2 are associated with severe developmental speech disturbances, and molecular studies indicate that impairment of Foxp2 may lead to dysregulation of genes involved in forebrain histogenesis. Here, anatomical and molecular phenotypes of the cortical neuron populations that express FOXP2 were characterized in mice. Additionally, Foxp2 was removed from the developing mouse cortex at different prenatal ages using two Cre-recombinase driver lines. Detailed molecular and circuit analyses were undertaken to identify potential disruptions of development. Surprisingly, the results demonstrate that Foxp2 function is not required for many functions that it has been proposed to regulate, and therefore plays a more limited role in cortical development than previously thought.

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A Composite Analysis of Flowering Time Regulation in Lettuce

Frontiers in Plant Science ◽

10.3389/fpls.2021.632708 ◽

2021 ◽

Vol 12 ◽

Author(s):

Rongkui Han ◽

Maria José Truco ◽

Dean O. Lavelle ◽

Richard W. Michelmore

Keyword(s):

Flowering Time ◽

Crop Production ◽

Phenotypic Diversity ◽

Model Organism ◽

Leafy Vegetables ◽

Vegetable Crops ◽

Comprehensive Overview ◽

Molecular Studies ◽

Functional Inference ◽

Delayed Flowering

Plants undergo profound physiological changes when transitioning from vegetative to reproductive growth. These changes affect crop production, as in the case of leafy vegetables. Lettuce is one of the most valuable leafy vegetable crops in the world. Past genetic studies have identified multiple quantitative trait loci (QTLs) that affect the timing of the floral transition in lettuce. Extensive functional molecular studies in the model organism Arabidopsis provide the opportunity to transfer knowledge to lettuce to explore the mechanisms through which genetic variations translate into changes in flowering time. In this review, we integrated results from past genetic and molecular studies for flowering time in lettuce with orthology and functional inference from Arabidopsis. This summarizes the basis for all known genetic variation underlying the phenotypic diversity of flowering time in lettuce and how the genetics of flowering time in lettuce projects onto the established pathways controlling flowering time in plants. This comprehensive overview reveals patterns across experiments as well as areas in need of further study. Our review also represents a resource for developing cultivars with delayed flowering time.

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Occurrence and Function of the Na+-Translocating NADH:Quinone Oxidoreductase in Prevotella spp.

Microorganisms ◽

10.3390/microorganisms7050117 ◽

2019 ◽

Vol 7 (5) ◽

pp. 117 ◽

Cited By ~ 3

Author(s):

Deusch ◽

Bok ◽

Schleicher ◽

Seifert ◽

Steuber

Keyword(s):

Anaerobic Metabolism ◽

Model Organism ◽

Mass Spectrometric ◽

Strictly Anaerobic ◽

Metabolic Potential ◽

Ruminal Bacteria ◽

Nadh:Quinone Oxidoreductase ◽

Rumen Microbiome ◽

Potential Activity ◽

And Function

Strictly anaerobic Prevotella spp. are characterized by their vast metabolic potential. As members of the Prevotellaceae family, they represent the most abundant organisms in the rumen and are typically found in monogastrics such as pigs and humans. Within their largely anoxic habitats, these bacteria are considered to rely primarily on fermentation for energy conservation. A recent study of the rumen microbiome identified multiple subunits of the Na+-translocating NADH:quinone oxidoreductase (NQR) belonging to different Prevotella spp. Commonly, the NQR is associated with biochemical energy generation by respiration. The existence of this Na+ pump in Prevotella spp. may indicate an important role for electrochemical Na+ gradients in their anaerobic metabolism. However, detailed information about the potential activity of the NQR in Prevotella spp. is not available. Here, the presence of a functioning NQR in the strictly anaerobic model organism P. bryantii B14 was verified by conducting mass spectrometric, biochemical, and kinetic experiments. Our findings propose that P. bryantii B14 and other Prevotella spp. retrieved from the rumen operate a respiratory NQR together with a fumarate reductase which suggests that these ruminal bacteria utilize a sodium motive force generated during respiratory NADH:fumarate oxidoreduction.

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The water flea Daphnia pulex (Cladocera, Daphniidae), a possible model organism to evaluate aspects of freshwater ecosystems

Crustaceana ◽

10.1163/15685403-00003948 ◽

2019 ◽

Vol 92 (11-12) ◽

pp. 1415-1426

Author(s):

Juan-Alejandro Norambuena ◽

Jorge Farías ◽

Patricio De los Ríos

Keyword(s):

Phylogenetic Trees ◽

Daphnia Pulex ◽

Model Organism ◽

Freshwater Ecosystems ◽

Intraspecific Diversity ◽

Molecular Tools ◽

Water Flea ◽

Future Studies ◽

Molecular Studies

Abstract Daphnia pulex is a freshwater planktonic crustacean, allegedly a cosmopolitan species, which is found in lentic ecosystems. The aim of this study was to conduct a literature review of D. pulex related to its life history and genetic variability, in order to mark a route for future studies. We noted that D. pulex is a model species on which ecological studies have been carried out, as well as molecular studies, in which its molecular diversity has been characterized and such in specimens from different environments: both pristine and under human influence. In particular those studies are highlighted, in which molecular tools have been used to construct phylogenetic trees for study intraspecific differences. Also, in some of these molecular studies, analyses of genetic, inter- and intraspecific diversity have been performed. In addition, analyses of protein expression in D. pulex and related species seem promising in evaluating the detailed role of this species.

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Molecular studies of corticosteroid binding globulin structure, biosynthesis and function

The Journal of Steroid Biochemistry and Molecular Biology ◽

10.1016/0960-0760(91)90300-t ◽

1991 ◽

Vol 40 (4-6) ◽

pp. 755-762 ◽

Cited By ~ 78

Author(s):

G.L. Hammond ◽

C.L. Smith ◽

D.A. Underhill

Keyword(s):

Corticosteroid Binding Globulin ◽

Molecular Studies ◽

And Function

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A role for mRNA trafficking and localized translation in peroxisome biogenesis and function?

Biochimica et Biophysica Acta (BBA) - Molecular Cell Research ◽

10.1016/j.bbamcr.2015.09.007 ◽

2016 ◽

Vol 1863 (5) ◽

pp. 911-921 ◽

Cited By ~ 11

Author(s):

Gal Haimovich ◽

Osnat Cohen-Zontag ◽

Jeffrey E. Gerst

Keyword(s):

Peroxisome Biogenesis ◽

Mrna Trafficking ◽

And Function

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The Hansenula polymorpha PER8 gene encodes a novel peroxisomal integral membrane protein involved in proliferation.

The Journal of Cell Biology ◽

10.1083/jcb.128.3.307 ◽

1995 ◽

Vol 128 (3) ◽

pp. 307-319 ◽

Cited By ~ 90

Author(s):

X Tan ◽

H R Waterham ◽

M Veenhuis ◽

J M Cregg

Keyword(s):

Amino Acid ◽

Membrane Protein ◽

Hansenula Polymorpha ◽

Methylotrophic Yeast ◽

Integral Membrane Protein ◽

Peroxisome Biogenesis ◽

Primary Sequence ◽

Zinc Finger Motifs ◽

Molecular Machinery

We previously described the isolation of mutants of the methylotrophic yeast Hansenula polymorpha that are defective in peroxisome biogenesis. Here, we describe the characterization of one of these mutants, per8, and the cloning of the PER8 gene. In either methanol or methylamine medium, conditions that normally induce the organelles, per8 cells contain no peroxisome-like structures and peroxisomal enzymes are located in the cytosol. The sequence of PER8 predicts that its product (Per8p) is a novel polypeptide of 34 kD, and antibodies against Per8p recognize a protein of 31 kD. Analysis of the primary sequence of Per8p revealed a 39-amino-acid cysteine-rich segment with similarity to the C3HC4 family of zinc-finger motifs. Overexpression of PER8 results in a markedly enhanced increase in peroxisome numbers. We show that Per8p is an integral membrane protein of the peroxisome and that it is concentrated in the membranes of newly formed organelles. We propose that Per8p is a component of the molecular machinery that controls the proliferation of this organelle.

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