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myotonin kinase (myotonic dystrophy-associated protein kinase, DMPK)
Function:
- modulation of cardiac contractility
- maintenance of proper cardiac conduction activity
- phosphorylates phospholamban
- activated in response to G protein second messengers
Cofactor: Mg+2
Structure:
- belongs to the Ser/Thr protein kinase family, DMPK subfamily
- classified as serine/threonine kinase because of homology to cAMP dependent protein kinase
- contains 1 protein kinase domain
- maintained in an inactive conformation by negative autoregulatory C-terminal coiled-coil region
- coiled-coil mediated oligomerization correlated with enhanced catalytic activity
- proteolytically cleavage near C-terminus correlated with enhanced catalytic activity
Alternative splicing:
- named isoforms=12
- at least one isoform may be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay
Expression:
- most isoforms are expressed in many tissues including heart, skeletal muscle, liver & brain
- isoform 2 is expressed in heart & skeletal muscle
- isoform 14 expressed only in brain, high levels in striatum, cerebellar cortex, pons
Pathology:
- defects in DMPK are the cause of myotonic dystrophy 1
Laboratory:
- DMPK genotyping
- DMPK gene mutation
- DMPK gene CTG repeats
- DMPK phenotype
Related
DMPK gene CTG repeats
DMPK gene mutation
DMPK genotyping
DMPK phenotype
myotonin protein kinase gene or myotonic dystrophy-1
General
serine/threonine kinase
Properties
STATE: active state
MOTIF: S/T phosphorylation site
kinase domain
MOTIF: ATP-binding site
NAME: ATP-binding site
Database Correlations
OMIM 160900
UniProt Q09013
References
- Ross CA, McInnis MG, Margolis RL, Li SH.
Genes with triplet repeats: candidate mediators of
neuropsychiatric disorders.
Trends Neurosci. 1993 Jul;16(7):254-60. Review.
PMID: 7689767
- GeneReviews
https://www.genecards.org/cgi-bin/carddisp.pl?gene=DMPK