The topological structure and function of Echinococcus granulosus lactate dehydrogenase, a tegumental transmembrane protein

2012 ◽  
Vol 184 (2) ◽  
pp. 109-117 ◽  
Author(s):  
Wenjia Gan ◽  
Zhaoping Zhang ◽  
Gang Lv ◽  
Hongxu Xu ◽  
Suxiang Zeng ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Echinococcus Granulosus ◽  
Topological Structure ◽  
Transmembrane Protein ◽  
Structure And Function ◽  
And Function

SIRPα signaling regulates podocyte structure and function

2013 ◽  
Vol 305 (6) ◽  
pp. F861-F870 ◽  
Author(s):  
Satoshi Takahashi ◽  
Mai Tomioka ◽  
Keiju Hiromura ◽  
Toru Sakairi ◽  
Hiroko Hamatani ◽  
...  
Keyword(s):  
Microscopic Examination ◽  
Transmembrane Protein ◽  
Regulatory Protein ◽  
Structure And Function ◽  
Mutant Mice ◽  
Dependent Manner ◽  
Wild Type ◽  
Cytoplasmic Region ◽  
Filtration Barrier ◽  
And Function

Signal-regulatory protein-α (SIRPα) is a transmembrane protein that contains tyrosine phosphorylation sites in its cytoplasmic region; two tyrosine phosphatases, SHP-1 and SHP-2, bind to these sites in a phosphorylation-dependent manner and transduce multiple intracellular signals. Recently, SIRPα was identified as one of the major tyrosine-phosphorylated proteins in the glomeruli and found to be expressed in podocytes. In the present study, we examined the role of SIRPα expression in podocytes using knockin mice (C57BL/6 background) expressing mutant SIRPα that lacks a cytoplasmic region (SIRPα-mutant mice). Light microscopic examination revealed no apparent morphological abnormalities in the kidneys of the SIRPα-mutant mice. On the other hand, electron microscopic examination revealed abnormal podocytes with irregular major processes and wider and flattened foot processes in the SIRPα-mutant mice compared with their wild-type counterparts. Significantly impaired renal functions and slight albuminuria were demonstrated in the SIRPα-mutant mice. In addition, adriamycin injection induced massive albuminuria together with focal glomerulosclerosis in the SIRPα-mutant mice, while their wild-type counterparts were resistant to adriamycin-induced nephropathy. These data demonstrate that SIRPα is involved in the regulation of podocyte structure and function as a filtration barrier under both physiological and pathological conditions.

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