Meprin-β activity modulates the β-catalytic subunit of protein kinase A in ischemia-reperfusion-induced acute kidney injury

Meprin metalloproteases have been implicated in the progression of kidney injury. Previous work from our group has shown that meprins proteolytically process the catalytic subunit of protein kinase A (PKA-C), resulting in decreased PKA-C kinase activity. The goal of the present study was to determine the PKA-C isoforms impacted by meprin-β and whether meprin-β expression affects downstream mediators of the PKA signaling pathway in ischemia-reperfusion (IR)-induced kidney injury. IR was induced in 12-wk-old male wild-type (WT) and meprin-β knockout (βKO) mice. Madin-Darby canine kidney cells transfected with meprin-β cDNA were also subjected to 2 h of hypoxia. Western blot analysis was used to evaluate levels of total PKA-C, PKA-Cα, PKA-Cβ, phosphorylated (p-)PKA-C, and p-ERK1/2. Meprin-β expression enhanced kidney injury as indicated by levels of neutrophil gelatinase-associated lipocalin and cystatin C. IR-associated decreases were observed in levels of p-PKA-C in kidney tissue from WT mice but not βKO mice, suggesting that meprin-β expression/activity is responsible for the in vivo reduction in kinase activity. Significant increases in levels of PKA-Cβ were observed in kidney lysates for WT mice but not βKO mice at 6 h post-IR. Proximal tubule PKA-Cβ increases in WT but not βKO kidneys were demonstrated by fluorescent microscopy. Furthermore, IR-induced injury was associated with significant increases in p-ERK levels for both genotypes. The present data demonstrate that meprin-β enhances IR-induced kidney injury in part by modulating mediators of the PKA-Cβ signaling pathway.

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Isoform-specific interactions between meprin metalloproteases and the catalytic subunit of protein kinase A: significance in acute and chronic kidney injury

AJP Renal Physiology ◽

10.1152/ajprenal.00167.2014 ◽

2015 ◽

Vol 308 (1) ◽

pp. F56-F68 ◽

Cited By ~ 11

Author(s):

Jean-Marie V. Niyitegeka ◽

Adam C. Bastidas ◽

Robert H. Newman ◽

Susan S. Taylor ◽

Elimelda Moige Ongeri

Keyword(s):

Protein Kinase ◽

Protein Kinase A ◽

Ischemia Reperfusion ◽

Kidney Injury ◽

Proximal Tubules ◽

Catalytic Subunit ◽

Specific Interactions ◽

Double Knockout ◽

Meprin Metalloproteases ◽

Kinase A

Meprin metalloproteases are abundantly expressed in the brush-border membranes of kidney proximal tubules. Meprins are implicated in ischemia-reperfusion (IR)-induced renal injury and diabetic nephropathy. The protein kinase A (PKA) signaling pathway modulates extracellular matrix metabolism in diabetic kidneys. The present study evaluated isoform-specific interactions between the catalytic subunit of PKA (PKA C) and meprins. To this end, cytosolic-enriched kidney proteins from meprin αβ double knockout mice, and purified forms of recombinant mouse PKA Cα, Cβ1, and Cβ2, were incubated with activated forms of either homomeric meprin A or meprin B. The cleaved protein products were subjected to SDS-PAGE and analyzed by Coomassie staining and Western blot analysis. While meprin A only cleaved PKA Cβ1, meprin B cleaved all three PKA C isoforms. Analysis of the proteolytic fragments by mass spectrometry revealed that meprin A and B cleave the PKA C isoforms at defined sites, resulting in unique cleavage products. Michaelis-Menten enzyme kinetics demonstrated that meprin B-mediated cleavage of PKA Cα occurs at a rate consistent with that of other physiologically relevant meprin substrates. Meprin cleavage decreased the kinase activity of PKA Cα, Cβ1, and Cβ2. PKA C levels were higher in diabetic kidneys, with evidence of in vivo fragmentation in wild-type diabetic kidneys. Confocal microscopy showed localization of meprin A in the glomeruli of diabetic kidneys. At 3 h post-IR, PKA C levels in proximal tubules decreased compared with distal tubules, which lack meprins. These data suggest that meprins may impact kidney injury, in part, via modulation of PKA signaling pathways.

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Modification of the retinoic acid signaling pathway by the catalytic subunit of protein kinase-A

Molecular Endocrinology ◽

10.1210/me.7.4.543 ◽

1993 ◽

Vol 7 (4) ◽

pp. 543-550 ◽

Cited By ~ 21

Author(s):

J. I. Huggenvik

Keyword(s):

Retinoic Acid ◽

Protein Kinase ◽

Protein Kinase A ◽

Signaling Pathway ◽

Catalytic Subunit ◽

Retinoic Acid Signaling ◽

Kinase A

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Thrombin and Collagen Induce a Feedback Inhibitory Signaling Pathway in Platelets Involving Dissociation of the Catalytic Subunit of Protein Kinase A from an NFκB-IκB Complex

Journal of Biological Chemistry ◽

10.1074/jbc.m109.077602 ◽

2010 ◽

Vol 285 (24) ◽

pp. 18352-18363 ◽

Cited By ~ 100

Author(s):

Stepan Gambaryan ◽

Anna Kobsar ◽

Natalia Rukoyatkina ◽

Sabine Herterich ◽

Joerg Geiger ◽

...

Keyword(s):

Protein Kinase ◽

Protein Kinase A ◽

Signaling Pathway ◽

Catalytic Subunit ◽

Inhibitory Signaling ◽

Kinase A

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Modification of the retinoic acid signaling pathway by the catalytic subunit of protein kinase-A.

Molecular Endocrinology ◽

10.1210/mend.7.4.8388997 ◽

1993 ◽

Vol 7 (4) ◽

pp. 543-550

Author(s):

J I Huggenvik ◽

M W Collard ◽

Y W Kim ◽

R P Sharma

Keyword(s):

Retinoic Acid ◽

Protein Kinase ◽

Protein Kinase A ◽

Signaling Pathway ◽

Catalytic Subunit ◽

Retinoic Acid Signaling ◽

Kinase A

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Meprin Interactions with the Catalytic Subunit of Protein Kinase A in Ischemia Reperfusion‐induced Renal Injury

The FASEB Journal ◽

10.1096/fasebj.29.1_supplement.807.11 ◽

2015 ◽

Vol 29 (S1) ◽

Author(s):

Jean‐Marie Niyitegeka ◽

Elimelda Moige Ongeri

Keyword(s):

Protein Kinase ◽

Protein Kinase A ◽

Renal Injury ◽

Ischemia Reperfusion ◽

Catalytic Subunit ◽

Kinase A

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cAMP has a protein kinase A independent regulatory effect on T cell proliferation, MAP kinase activity and on mRNA levels for IL-2 and INF-gamma

Immunology Letters ◽

10.1016/s0165-2478(97)87084-8 ◽

1997 ◽

Vol 56 (1-3) ◽

pp. 65

Author(s):

B Hofmann

Keyword(s):

Cell Proliferation ◽

T Cell ◽

Protein Kinase ◽

Map Kinase ◽

Protein Kinase A ◽

Kinase Activity ◽

T Cell Proliferation ◽

Mrna Levels ◽

Regulatory Effect ◽

Kinase A

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Activity, expression and function of a second Drosophila protein kinase A catalytic subunit gene.

Genetics ◽

10.1093/genetics/141.4.1507 ◽

1995 ◽

Vol 141 (4) ◽

pp. 1507-1520 ◽

Cited By ~ 5

Author(s):

A Meléndez ◽

W Li ◽

D Kalderon

Keyword(s):

Protein Kinase ◽

Protein Kinase A ◽

Essential Gene ◽

Sequence Similarity ◽

Catalytic Subunit ◽

Subunit Gene ◽

Drosophila Protein ◽

Pka Catalytic Subunit ◽

Kinase A

Abstract The DC2 gene was isolated previously on the basis of sequence similarity to DC0, the major Drosophila protein kinase A (PKA) catalytic subunit gene. We show here that the 67-kD Drosophila DC2 protein behaves as a PKA catalytic subunit in vitro. DC2 is transcribed in mesodermal anlagen of early embryos. This expression depends on dorsal but on neither twist nor snail activity. DC2 transcriptional fusions mimic this embryonic expression and are also expressed in subsets of cells in the optic lamina, wing disc and leg discs of third instar larvae. A saturation screen of a small deficiency interval containing DC2 for recessive lethal mutations yielded no DC2 alleles. We therefore isolated new deficiencies to generate deficiency trans-heterozygotes that lacked DC2 activity. These animals were viable and fertile. The absence of DC2 did not affect the viability or phenotype of imaginal disc cells lacking DC0 activity or embryonic hatching of animals with reduced DC0 activity. Furthermore, transgenes expressing DC2 from a DC0 promoter did not efficiently rescue a variety of DC0 mutant phenotypes. These observations indicate that DC2 is not an essential gene and is unlikely to be functionally redundant with DC0, which has multiple unique functions during development.

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