Mandibuloacral dysplasia caused by homozygosity for the R527H mutation in lamin A/C

Shen, Joseph; Brown, Charlotte A.; Lupski, James R.; Potocki, Lorraine

doi:10.1136/jmg.40.11.854

Cited by 57 publications

(44 citation statements)

References 35 publications

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“…The most common genetic cause of MADA is the homozygous p.Arg527His LMNA mutation. 1,3,4 Furthermore, the homozygous p.Arg527Cys LMNA mutation results in early and severe MAD and progeria. 7 According to the computational structure prediction, a basic arginine at position 527 of the wildtype lamin A, forms a salt bridge with the glutamate at position 537, thus stabilizing the structure of the conserved C-terminal IG-like domain of this protein.…”

Section: Discussionmentioning

confidence: 99%

“…2 The most common mutation reported in patients with MADA is the homozygous p.Arg527His substitution in exon 9 of the LMNA gene. 1,3,4 Other LMNA mutations resulting in MAD are homozygous p.Ala529Val and compound p.Arg527His/Val440Met. 5,6 MAD with progeria-like features was described in relation to the homozygous p.Arg527Cys, homozygous p.Lys542Asn, homozygous p.Arg471Cys, compound p.Thr528Met/Met540Thr, and compound p.Arg471Cys/ Arg527Cys LMNA mutations.…”

Section: Introductionmentioning

confidence: 99%

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A novel homozygous p.Arg527Leu LMNA mutation in two unrelated Egyptian families causes overlapping mandibuloacral dysplasia and progeria syndrome

et al. 2012

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A novel homozygous p.Arg527Leu LMNA mutation in two unrelated Egyptian families causes overlapping mandibuloacral dysplasia and progeria syndrome

et al. 2012

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“…Disorder Type 2B1 (CMT2B1, MIM# 605588) (De Sandre-Giovannoli, et al, 2002), mandibuloacral dysplasia (MAD, MIM# 248370) (Novelli, et al, 2002;Shen, et al, 2003),…”

mentioning

confidence: 99%

Novel LMNA mutations in patients with Emery-Dreifuss muscular dystrophy and functional characterization of four LMNA mutations

Scharner

Brown²,

Bower

et al. 2011

Hum. Mutat.

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“…Lamin A mutants defective for processing could not restore p16 ink4A -mediated arrest or stabilize pRB, suggesting that appropriate modification of lamin A is important for maintaining normal levels of pRB. A mandibuloacral dysplasia (MAD)-associated mutant LMNA allele (R527H) also failed to restore signaling through the p16 ink4a /pRB pathway (49,62). Surprisingly, however, other laminopathy alleles, including another MAD mutant, adequately restored p16 ink4a -mediated cell cycle arrest.…”

mentioning

confidence: 99%

Stabilization of the Retinoblastoma Protein by A-Type Nuclear Lamins Is Required for INK4A-Mediated Cell Cycle Arrest

Nitta¹,

Jameson²,

Kudlow

et al. 2006

Molecular and Cellular Biology

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Mutations in the LMNA gene, which encodes all A-type lamins, including lamin A and lamin C, cause a variety of tissue-specific degenerative diseases termed laminopathies. Little is known about the pathogenesis of these disorders. Previous studies have indicated that A-type lamins interact with the retinoblastoma protein (pRB). Here we probe the functional consequences of this association and further examine links between nuclear structure and cell cycle control. Since pRB is required for cell cycle arrest by p16 ink4a , we tested the responsiveness of multiple lamin A/C-depleted cell lines to overexpression of this CDK inhibitor and tumor suppressor. We find that the loss of A-type lamin expression results in marked destabilization of pRB. This reduction in pRB renders cells resistant to p16 ink4a -mediated G 1 arrest. Reintroduction of lamin A, lamin C, or pRB restores p16 ink4a -responsiveness to Lmna ؊/؊ cells. An array of lamin A mutants, representing a variety of pathologies as well as lamin A processing mutants, was introduced into Lmna ؊/؊ cells. Of these, a mutant associated with mandibuloacral dysplasia (MAD R527H), as well as two lamin A processing mutants, but not other disease-associated mutants, failed to restore p16 ink4a responsiveness. Although our findings do not rule out links between altered pRB function and laminopathies, they fail to support such an assertion. These findings do link lamin A/C to the functional activation of a critical tumor suppressor pathway and further the possibility that somatic mutations in LMNA contribute to tumor progression.A-type lamins are intermediate filament proteins that have been linked to the organization and maintenance of nuclear structure. In most differentiated tissues, A-type lamins (predominantly lamins A and C), along with lamin B, comprise the meshwork underlying the inner nuclear membrane known as the nuclear lamina (63). Unlike lamin C, lamin A contains a carboxy-terminal CaaX motif and must undergo a series of posttranslational modifications to form the mature lamin A (77). In particular, the cysteine of the CaaX motif in lamin A is isoprenylated, followed by cleavage of the aaX and carboxymethylation of the C-terminal cysteine (72). Lastly, a second cleavage event by Zmpste24 removes the last 15 amino acids to yield the mature lamin A (3, 13, 74).Mutations within the LMNA gene cause a variety of human disorders collectively known as laminopathies. These include progeria syndromes and dystrophies associated with skeletal muscle and adipose tissue (5,10,15,19,45,58). Mice lacking A-type lamins or deficient in processing lamin A develop skeletal and cardiac muscular dystrophies, thus confirming the importance of A-type lamins for muscle differentiation and/or maintenance (52, 65). The mechanism by which mutations in A-type lamins generate tissue-specific disorders is unknown. However, one model posits that lamin A/C regulates gene expression in differentiated tissue by coordinating the activity of key transcription factors.A-type lamins localize to p...

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Mandibuloacral dysplasia caused by homozygosity for the R527H mutation in lamin A/C

Cited by 57 publications

References 35 publications

A novel homozygous p.Arg527Leu LMNA mutation in two unrelated Egyptian families causes overlapping mandibuloacral dysplasia and progeria syndrome

A novel homozygous p.Arg527Leu LMNA mutation in two unrelated Egyptian families causes overlapping mandibuloacral dysplasia and progeria syndrome

Novel LMNA mutations in patients with Emery-Dreifuss muscular dystrophy and functional characterization of four LMNA mutations

Stabilization of the Retinoblastoma Protein by A-Type Nuclear Lamins Is Required for INK4A-Mediated Cell Cycle Arrest

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