scholarly journals Hsp90 and Client Protein Maturation

2011 ◽  
pp. 33-44 ◽  
Author(s):  
Natalie Wayne ◽  
Parul Mishra ◽  
Daniel N. Bolon
Keyword(s):  
Client Protein ◽  
Protein Maturation

scholarly journals Cryo-EM structures reveal a multistep mechanism of Hsp90 activation by co-chaperone Aha1

2020 ◽  
Author(s):  
Yanxin Liu ◽  
Ming Sun ◽  
Alexander G. Myasnikov ◽  
Daniel Elnatan ◽  
Nicolas Delaeter ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Large Scale ◽  
Atp Hydrolysis ◽  
Activation Mechanism ◽  
Client Protein ◽  
Protein Maturation ◽  
Structural Framework ◽  
Cryo Electron Microscopy ◽  
Client Proteins ◽  
Rate Limiting

AbstractHsp90 is a ubiquitous molecular chaperone that facilitates the folding and maturation of hundreds of cellular “client” proteins. The ATP-driven client maturation process is regulated by a large number of co-chaperones. Among them, Aha1 is the most potent activator of Hsp90 ATPase activity and thus dramatically affects Hsp90’s client proteins. To understand the Aha1 activation mechanism, we determined full-length Hsp90:Aha1 structures in six different states by cryo-electron microscopy, including nucleotide-free semi-closed, nucleotide-bound pre-hydrolysis, and semi-hydrolyzed states. Our structures demonstrate that the two Aha1 domains can each interact with Hsp90 in two different modes, uncovering a complex multistep activation mechanism. The results show that Aha1 accelerates the chemical step of ATP hydrolysis like a conventional enzyme, but most unusually, catalyzes the rate-limiting large-scale conformational changes of Hsp90 fundamentally required for ATP hydrolysis. Our work provides a structural framework to guide small molecule development targeting this critical modulator of client protein maturation.

A T.E.M. study of mouse mammary epithelial cell secretory differentiation cultured on collagen and Matrigel

1991 ◽  
Vol 49 ◽  
pp. 188-189
Author(s):  
W.N. Bentham ◽  
V. Rocha
Keyword(s):  
Cell Culture ◽  
Mammary Epithelial ◽  
Secretory Process ◽  
Cell Culture System ◽  
Protein Maturation ◽  
Cell Culture Techniques ◽  
Culture Techniques ◽  
Mouse Mammary Epithelial Cell ◽  
Secretory Differentiation

It has been an interest of our lab to develop a mammary epethelial cell culture system that faithfully duplicates the in vivo condition of the lactating gland. Since the introduction of collagen as a matrix on which cells are cultivated other E.C.M. type matrices have been made available and are used in many cell culture techniques. We have previously demonstrated that cells cultured on collagen and Matrigel do not differentiate as they do in vivo. It seems that these cultures often produce cells that show a disruption in the secretory process. The appearance of large ribosomal studded vesicles, that specifically label with antibody to casein, suggest an interruption of both protein maturation and secretion at the E.R. to golgi transition. In this report we have examined cultures on collagen and Matrigel at relative high and low seeding densities and compared them to cells from the in vivo condition.

430: Modulation of Heat-Shock Protein 90 (HSP90) Client Protein Expression in Prostate Cancer Cells by a Novel Novobiocin Analog

2006 ◽  
Vol 175 (4S) ◽  
pp. 140-140
Author(s):  
Manlio A. Goetzl ◽  
Brian S. Blagg ◽  
Benjamin Cronk ◽  
Len Neckers ◽  
Jeffrey M. Holzbeierlein
Keyword(s):  
Prostate Cancer ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Protein Expression ◽  
Cancer Cells ◽  
Heat Shock Protein 90 ◽  
Client Protein ◽  
Prostate Cancer Cells ◽  
Hsp90 Client Protein

Plant immunophilins: functional versatility beyond protein maturation

2005 ◽  
Vol 166 (3) ◽  
pp. 753-769 ◽  
Author(s):  
Patrick Romano ◽  
Julie Gray ◽  
Peter Horton ◽  
Sheng Luan
Keyword(s):  
Protein Maturation ◽  
Functional Versatility

scholarly journals The Yeast Scaffold Proteins Isu1p and Isu2p Are Required inside Mitochondria for Maturation of Cytosolic Fe/S Proteins

2004 ◽  
Vol 24 (11) ◽  
pp. 4848-4857 ◽  
Author(s):  
Jana Gerber ◽  
Karina Neumann ◽  
Corinna Prohl ◽  
Ulrich Mühlenhoff ◽  
Roland Lill
Keyword(s):  
Iron Homeostasis ◽  
De Novo ◽  
Mitochondrial Targeting ◽  
Protein Maturation ◽  
Iron Sulfur Cluster ◽  
Subcellular Compartment ◽  
S Protein ◽  
Iron Sulfur ◽  
Protein Biogenesis ◽  
S Proteins

ABSTRACT Iron-sulfur (Fe/S) proteins are located in mitochondria, cytosol, and nucleus. Mitochondrial Fe/S proteins are matured by the iron-sulfur cluster (ISC) assembly machinery. Little is known about the formation of Fe/S proteins in the cytosol and nucleus. A function of mitochondria in cytosolic Fe/S protein maturation has been noted, but small amounts of some ISC components have been detected outside mitochondria. Here, we studied the highly conserved yeast proteins Isu1p and Isu2p, which provide a scaffold for Fe/S cluster synthesis. We asked whether the Isu proteins are needed for biosynthesis of cytosolic Fe/S clusters and in which subcellular compartment the Isu proteins are required. The Isu proteins were found to be essential for de novo biosynthesis of both mitochondrial and cytosolic Fe/S proteins. Several lines of evidence indicate that Isu1p and Isu2p have to be located inside mitochondria in order to perform their function in cytosolic Fe/S protein maturation. We were unable to mislocalize Isu1p to the cytosol due to the presence of multiple, independent mitochondrial targeting signals in this protein. Further, the bacterial homologue IscU and the human Isu proteins (partially) complemented the defects of yeast Isu protein-depleted cells in growth rate, Fe/S protein biogenesis, and iron homeostasis, yet only after targeting to mitochondria. Together, our data suggest that the Isu proteins need to be localized in mitochondria to fulfill their functional requirement in Fe/S protein maturation in the cytosol.

scholarly journals Correction to: The NMR contribution to protein–protein networking in Fe–S protein maturation

2018 ◽  
Vol 23 (4) ◽  
pp. 687-687 ◽  
Author(s):  
Lucia Banci ◽  
Francesca Camponeschi ◽  
Simone Ciofi‑Baffoni ◽  
Mario Piccioli
Keyword(s):  
Protein Maturation ◽  
S Protein
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