A multiprotein complex polarisome nucleates actin cables for polarized cell growth in budding yeast and filamentous fungi. However, the dynamic regulations of polarisome proteins in polymerizing actin under physiological and stress conditions remains unknown. We identify a previously functionally unknown polarisome member, actin-interacting-protein 5 (Aip5), which promotes actin assembly synergistically with formin Bni1. Aip5-C terminus is responsible for its activities by interacting with G-actin and Bni1. Through N-terminal intrinsically disordered region, Aip5 forms high-order oligomers and generate cytoplasmic condensates under the stresses conditions. The molecular dynamics and reversibility of Aip5 condensates are regulated by scaffolding protein Spa2 via liquid-liquid phase separation both in vitro and in vivo. In the absence of Spa2, Aip5 condensates hamper cell growth and actin cable structures under stress treatment. The present study reveals the mechanisms of actin assembly for polarity establishment and the adaptation in stress conditions to protect actin assembly by protein phase separation.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6838200PMC
http://dx.doi.org/10.1038/s41467-019-13125-1DOI Listing

Publication Analysis

Top Keywords

actin assembly
12
cell growth
8
stress conditions
8
aip5 condensates
8
phase separation
8
actin
7
aip5
5
polarisome
4
polarisome scaffolder
4
scaffolder spa2-mediated
4

Similar Publications

Liver fibrosis is a prevalent liver disease associated with significant morbidity, and the activation of hepatic stellate cells (HSCs) serves as the primary causative factor driving the progression of liver fibrosis. However, capillarization of liver sinusoidal endothelial cells (LSECs) induced by hepatic fibrosis can reduce nitric oxide (NO) production and bioavailability, which consequently loses the ability to retain HSCs dormant, leading to amplified HSCs activation. Herein, an elaborate micelle (VN-M@BN) loaded with benazepril (BN) was constructed by self-assembly of polymeric NO donor, aiming for the controlled release of NO in liver fibrosis lesions thereby impeding the progression of liver fibrosis.

View Article and Find Full Text PDF

Transforming an ATP-dependent enzyme into a dissipative, self-assembling system.

Nat Chem Biol

January 2025

Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA.

Nucleoside triphosphate (NTP)-dependent protein assemblies such as microtubules and actin filaments have inspired the development of diverse chemically fueled molecular machines and active materials but their functional sophistication has yet to be matched by design. Given this challenge, we asked whether it is possible to transform a natural adenosine 5'-triphosphate (ATP)-dependent enzyme into a dissipative self-assembling system, thereby altering the structural and functional mode in which chemical energy is used. Here we report that FtsH (filamentous temperature-sensitive protease H), a hexameric ATPase involved in membrane protein degradation, can be readily engineered to form one-dimensional helical nanotubes.

View Article and Find Full Text PDF

Identification and subcellular localization of the chaperonin NbCCTβ in Nosema bombycis.

Gene

January 2025

College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; Sericulture Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China. Electronic address:

Nosema bombycis, the causative agent of pebrine disease, poses a significant threat to the silkworm industry due to its negative impact on silkworm health and productivity. The chaperonin-containing tailless complex polypeptide (CCT) plays a crucial role in protein folding, and its β subunit (CCTβ) is essential for the proper folding of cytoskeletal proteins, such as actin and tubulin. In this study, we cloned and expressed the NbCCTβ gene from N.

View Article and Find Full Text PDF

Sequential recruitment of F-BAR proteins controls cytoskeletal crosstalk at the yeast bud neck.

Curr Biol

January 2025

Department of Biology, Rosenstiel Basic Medical Science Research Center, Brandeis University, 415 South Street, Waltham, MA 02454, USA. Electronic address:

In vivo functions of the septin and actin cytoskeletons are closely intertwined, yet the mechanisms underlying septin-actin crosstalk have remained poorly understood. Here, we show that the yeast-bud-neck-associated Fes/CIP4 homology Bar-amphiphysin-Rvs (F-BAR) protein suppressor of yeast profilin 1 (Syp1)/FCHo uses its intrinsically disordered region (IDR) to directly bind and bundle filamentous actin (F-actin) and to physically link septins and F-actin. Interestingly, the only other F-BAR protein found at the neck during bud development, Hof1, has related activities and also potently inhibits the bud-neck-associated formin Bnr1.

View Article and Find Full Text PDF

PARL regulates porcine oocyte meiotic maturation by mediating mitochondrial activity.

Theriogenology

January 2025

Anhui Province Key Laboratory of Local Livestock and Poultry, Genetical Resource Conservation and Breeding, College of Animal Science and Technology, Anhui Agricultural University, Hefei, 230036, China. Electronic address:

Article Synopsis
  • PARL is a rhomboid membrane protein essential for mitochondrial function and plays a significant role in oocyte maturation, though its specific effects are not well understood.
  • Inhibiting PARL expression resulted in reduced polar body extrusion and abnormal embryo development, along with negative impacts on mitochondrial activity and increased oxidative stress in porcine oocytes.
  • PARL deficiency also altered the expression of key genes related to mitochondrial function and DNA integrity, emphasizing its critical role in the maturation process of oocytes.
View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!