scholarly journals Membrane Proteins Are Dramatically Less Conserved than Water-Soluble Proteins across the Tree of Life

2016 ◽  
Vol 33 (11) ◽  
pp. 2874-2884 ◽  
Author(s):  
Victor Sojo ◽  
Christophe Dessimoz ◽  
Andrew Pomiankowski ◽  
Nick Lane
2014 ◽  
Vol 395 (12) ◽  
pp. 1365-1377 ◽  
Author(s):  
Grant Kemp ◽  
Florian Cymer

Abstract Membrane proteins are important mediators between the cell and its environment or between different compartments within a cell. However, much less is known about the structure and function of membrane proteins compared to water-soluble proteins. Moreover, until recently a subset of membrane proteins, those shorter than 100 amino acids, have almost completely evaded detection as a result of technical difficulties. These small membrane proteins (SMPs) have been underrepresented in most genomic and proteomic screens of both pro- and eukaryotic cells and, hence, we know much less about their functions in both. Currently, through a combination of bioinformatics, ribosome profiling, and more sensitive proteomics, large numbers of SMPs are being identified and characterized. Herein we describe recent advances in identifying SMPs from genomic and proteomic datasets and describe examples where SMPs have been successfully characterized biochemically. Finally we give an overview of identified functions of SMPs and speculate on the possible roles SMPs play in the cell.


Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 726
Author(s):  
Chung-Ling Lu ◽  
Jinoh Kim

Cells use membrane-bound carriers to transport cargo molecules like membrane proteins and soluble proteins, to their destinations. Many signaling receptors and ligands are synthesized in the endoplasmic reticulum and are transported to their destinations through intracellular trafficking pathways. Some of the signaling molecules play a critical role in craniofacial morphogenesis. Not surprisingly, variants in the genes encoding intracellular trafficking machinery can cause craniofacial diseases. Despite the fundamental importance of the trafficking pathways in craniofacial morphogenesis, relatively less emphasis is placed on this topic, thus far. Here, we describe craniofacial diseases caused by lesions in the intracellular trafficking machinery and possible treatment strategies for such diseases.


1979 ◽  
Vol 557 (2) ◽  
pp. 331-339 ◽  
Author(s):  
L. Vitello ◽  
G.C. Kresheck ◽  
R.J. Albers ◽  
J.E. Erman ◽  
G. Vanderkooi

1999 ◽  
Vol 112 (5) ◽  
pp. 613-622 ◽  
Author(s):  
J.V. Jester ◽  
T. Moller-Pedersen ◽  
J. Huang ◽  
C.M. Sax ◽  
W.T. Kays ◽  
...  

In vivo corneal light scattering measurements using a novel confocal microscope demonstrated greatly increased backscatter from corneal stromal fibrocytes (keratocytes) in opaque compared to transparent corneal tissue in both humans and rabbits. Additionally, two water-soluble proteins, transketolase (TKT) and aldehyde dehydrogenase class 1 (ALDH1), isolated from rabbit keratocytes showed unexpectedly abundant expression (approximately 30% of the soluble protein) in transparent corneas and markedly reduced levels in opaque scleral fibroblasts or keratocytes from hazy, freeze injured regions of the cornea. Together these data suggest that the relatively high expressions of TKT and ALDH1 contribute to corneal transparency in the rabbit at the cellular level, reminiscent of enzyme-crystallins in the lens. We also note that ALDH1 accumulates in the rabbit corneal epithelial cells, rather than ALDH3 as seen in other mammals, consistent with the taxon-specificity observed among lens enzyme-crystallins. Our results suggest that corneal cells, like lens cells, may preferentially express water-soluble proteins, often enzymes, for controlling their optical properties.


2012 ◽  
Vol 65 (11) ◽  
pp. 1548 ◽  
Author(s):  
Yuki Kohno ◽  
Nobuhumi Nakamura ◽  
Hiroyuki Ohno

Mixtures of some ionic liquids (ILs) and water show reversible phase change between a homogeneous mixture and phase-separated state by a small change in temperature. Some water-soluble proteins have been migrated from the aqueous to the IL phase. When tetrabutylphosphonium 2,4,6-trimethylbenzenesulfonate was used as an IL, cytochrome c (Cyt.c) was found to be extracted from the water phase to the IL phase. Conversely, both horseradish peroxidase (HRP) and azurin remained in the aqueous phase. This selective extraction was comprehended to be due to the difference in solubility of these proteins in both phases. The separated aqueous phase contained a small amount of IL, which induced the salting-out of Cyt.c. On the other hand, condensed IL phase promoted the salting-in of Cyt.c. As a result, Cyt.c was preferably dissolved in the hydrated IL phase rather than aqueous phase. In the case of HRP, there was only a salting-out profile upon increasing the concentration of IL, which induced selective dissolution of HRP in the aqueous phase. These results clearly suggest that the profile of salting-out and salting-in for proteins is the key factor to facilitate the selective extraction of proteins from aqueous to the IL phase.


Author(s):  
L. A. Chudinova ◽  
◽  
D. R. Yusupov ◽  

We studied the growth rate of rye seedlings, as well as the dynamics of the content of soluble proteins and proline in the shoots during their adaptation to sharp (300 mM NaCl once, exposure time 9 days) and gradual (100 mM NaCl, then 100 mM NaCl after 2 days to the final concentration of 400 mM) salinity with sodium chloride in the presence or absence of thermal hardening (+40°C, 3 h). The established dy-namics of the content of proline and soluble proteins in the shoots suggests that the formation of re-sistance to salinity is determined by the high constitutive level of proline, as well as the stress-inducible synthesis of proline and water-soluble proteins. Thermal pretreatment of the seedlings stimulated their constitutive stability to a greater extent. The detected metabolic changes are obviously related to one of the possible mechanisms of the protective effect of thermal hardening on subsequent salinization.


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