Substrate selectivity and sensitivity to inhibition by FK506 and cyclosporin A of calcineurin heterodimers composed of the α or β catalytic subunit

Perrino, Brian A.; Wilson, Andrew J.; Ellison, Patricia A.; Clapp, Lucie H.

doi:10.1046/j.1432-1033.2002.03040.x

Cited by 46 publications

(52 citation statements)

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“…In addition, targeted gene knockouts in mice of ␣ or ␤ forms of the CaNA subunit revealed different roles in the cell physiology of muscle cells (␤ [9]) and hippocampus cells (␣ [100]). Finally, biochemical studies on the CaNA-␣ and -␤ isoforms in humans have shown that the two isoforms display substrate specific differences in their sensitivity to known inhibitors of calcineurin activity (71), providing a biochemical basis for isoform differences in function.…”

Section: Discussionmentioning

confidence: 99%

Protein Phosphatase 2B (PP2B, Calcineurin) in Paramecium: Partial Characterization Reveals That Two Members of the Unusually Large Catalytic Subunit Family Have Distinct Roles in Calcium-Dependent Processes

et al. 2010

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We characterized the calcineurin (CaN) gene family, including the subunits CaNA and CaNB, based upon sequence information obtained from the Paramecium genome project. Paramecium tetraurelia has seven subfamilies of the catalytic CaNA subunit and one subfamily of the regulatory CaNB subunit, with each subfamily having two members of considerable identity on the amino acid level (>55% between subfamilies, >94% within CaNA subfamilies, and full identity in the CaNB subfamily). Within CaNA subfamily members, the catalytic domain and the CaNB binding region are highly conserved and molecular modeling revealed a three-dimensional structure almost identical to a human ortholog. At 14 members, the size of the CaNA family is unprecedented, and we hypothesized that the different CaNA subfamily members were not strictly redundant and that at least some fulfill different roles in the cell. This was tested by selecting two phylogenetically distinct members of this large family for posttranscriptional silencing by RNA interference. The two targets resulted in differing effects in exocytosis, calcium dynamics, and backward swimming behavior that supported our hypothesis that the large, highly conserved CaNA family members are not strictly redundant and that at least two members have evolved diverse but overlapping functions. In sum, the occurrence of CaN in Paramecium spp., although disputed in the past, has been established on a molecular level. Its role in exocytosis and ciliary beat regulation in a protozoan, as well as in more complex organisms, suggests that these roles for CaN were acquired early in the evolution of this protein family.

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Section: Discussionmentioning

confidence: 99%

Protein Phosphatase 2B (PP2B, Calcineurin) in Paramecium: Partial Characterization Reveals That Two Members of the Unusually Large Catalytic Subunit Family Have Distinct Roles in Calcium-Dependent Processes

et al. 2010

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“…In the heart, each isoform comprises approximately 50% of the total catalytic isoform expression (8), although calcineurin A␤ protein levels increase during hypertrophy while A␣ levels remain unchanged (45). At the biochemical level, calcineurin A␣ and A␤ differ slightly in their enzymatic properties such that A␣ has a lower K m and a higher V max toward the phosphorylated RII peptide than does A␤ (35). While calcineurin A␣ and A␤ each show identical calmodulin dissociation rates and similar inhibition curves to the autoinhibitory peptide, the A␣ isoform is more sensitive to FK506 inhibition than is A␤ (35).…”

Section: Discussionmentioning

confidence: 99%

“…At the biochemical level, calcineurin A␣ and A␤ differ slightly in their enzymatic properties such that A␣ has a lower K m and a higher V max toward the phosphorylated RII peptide than does A␤ (35). While calcineurin A␣ and A␤ each show identical calmodulin dissociation rates and similar inhibition curves to the autoinhibitory peptide, the A␣ isoform is more sensitive to FK506 inhibition than is A␤ (35). Collectively, these previous reports indicate that calcineurin A␣ and A␤ are subject to different levels of regulation in multiple tissues and that each has slightly different biochemical properties.…”

Section: Discussionmentioning

confidence: 99%

Altered Skeletal Muscle Phenotypes in Calcineurin Aα and Aβ Gene-Targeted Mice

Parsons

Wilkins

Bueno

et al. 2003

Molecular and Cellular Biology

147

140

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Calcineurin is a calcium-regulated serine-threonine protein phosphatase that controls developmental and inducible biological responses in diverse cell types, in part through activation of the transcription factor nuclear factor of activated T cells (NFAT). In skeletal muscle, calcineurin has been implicated in the regulation of myoblast differentiation, hypertrophy of mature myofibers, and fiber type switching in response to alterations in intracellular calcium concentration. However, considerable disagreement persists about the functional role of calcineurin signaling in each of these processes. Here we evaluated the molecular phenotypes of skeletal muscle from both calcineurin A␣ and calcineurin A␤ gene-targeted mice. Calcineurin A␣ was observed to be the predominant catalytic isoform expressed in nearly all skeletal muscles examined. Neither calcineurin A␣ or A␤ null mice showed any gross growth-related alterations in skeletal muscle, nor was fiber size or number altered in glycolytic/fast muscle types. In contrast, both calcineurin A␣ and A␤ gene-targeted mice demonstrated an alteration in myofiber number in the soleus, an oxidative/slow-type muscle. More significantly, calcineurin A␣ and A␤ gene-targeted mice showed a dramatic down-regulation in the oxidative/slow fiber type program in multiple muscles (both slow and fast). Associated with this observation, NFAT-luciferase reporter transgenic mice showed significantly greater activity in slow fiber-containing muscles than in fast. However, only calcineurin A␣ null mice showed a defect in NFAT nuclear occupancy or NFAT-luciferase transgene activity in vivo. Collectively, our results suggest that calcineurin signaling plays a critical role in regulating skeletal muscle fiber type switching but not hypertrophy. Our results also suggest that fiber type switching occurs through an NFAT-independent mechanism.Calcineurin is a calcium-calmodulin-activated serine-threonine phosphatase composed of a catalytic A subunit (59 to 62 kDa) and a calcium-binding regulatory B subunit (19 kDa). Three catalytic genes (A subunit) have been identified in vertebrate species, of which calcineurin A␣ and calcineurin A␤ are ubiquitously expressed, while calcineurin A␥ expression is restricted to the testis and brain (11,23,38). Receptor stimulation that promotes a sustained elevation in intracellular calcium concentration leads to a direct activation of calcineurin, which in turn facilitates alterations in gene expression through transcriptional effector proteins (11,23,38). One such mechanism involves a family of transcriptional regulators referred to as nuclear factor of activated T cells (NFAT), which are normally sequestered in the cytoplasm in a hyperphosphorylated state (36). Activated calcineurin then directly binds NFAT transcription factors in the cytoplasm, resulting in their dephosphorylation and subsequent translocation into the nucleus. Once in the nucleus, NFAT factors function as important coinducers of calcium-activated, inducible gene expression in multiple cell typ...

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“…Calcineurin (Cn) 3 , a heterodimeric serine/threonine phosphatase enzyme, is the only protein phosphatase dependent on Ca 2ϩ . The enzyme is composed of an A subunit and a B subunit.…”

confidence: 99%

“…The other isoforms appear in all tissues, albeit in varying ratios (2 ). These isoforms differ quite extensively in their enzyme kinetics and physiological functions (3,4 ). For instance, lack of CnA␤, the predominant isoform in lymphocytes, leads to inadequate T-cell development and a compromised immune response in mice (5 ).…”

confidence: 99%

Molecular Diagnostics of Calcineurin-Related Pathologies

Musson

Cobbaert²,

Smit³

2012

Clinical Chemistry

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BACKGROUND The Ca2+-dependent protein phosphatase enzyme calcineurin (Cn) (protein phosphatase 3) is best known for its role as director of the adaptive immune response. One of its principal substrates is the nuclear factor of activated T cells (NFAT), which translocates to the nucleus after dephosphorylation to mediate gene transcription. Drugs targeting Cn (the Cn inhibitors tacrolimus and cyclosporin A) have revolutionized posttransplantation therapy in allograft recipients by considerably reducing rejection rates. CONTENT Owing primarily to intensive study of the side effects of the Cn inhibitors, the unique importance of Cn and Cn/NFAT signaling in the normal physiological processes of many other cell and tissue types is becoming more evident. During the last decade, it has become clear that an extensive and diverse array of clinical conditions can be traced back, at least in part, to a disturbed Cn-signaling axis. Hence, both diagnostics and therapeutic monitoring could benefit from a technique that conveniently reads out Cn/NFAT operative status. SUMMARY This review outlines the current knowledge on the pathologic conditions that have calcineurin as a common denominator and reports on the progress that has been made toward successfully applying Cn and Cn/NFAT activity markers in molecular diagnostics.

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Substrate selectivity and sensitivity to inhibition by FK506 and cyclosporin A of calcineurin heterodimers composed of the α or β catalytic subunit

Cited by 46 publications

References 45 publications

Protein Phosphatase 2B (PP2B, Calcineurin) in Paramecium: Partial Characterization Reveals That Two Members of the Unusually Large Catalytic Subunit Family Have Distinct Roles in Calcium-Dependent Processes

Protein Phosphatase 2B (PP2B, Calcineurin) in Paramecium: Partial Characterization Reveals That Two Members of the Unusually Large Catalytic Subunit Family Have Distinct Roles in Calcium-Dependent Processes

Altered Skeletal Muscle Phenotypes in Calcineurin Aα and Aβ Gene-Targeted Mice

Molecular Diagnostics of Calcineurin-Related Pathologies

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