Alternate promoter usage generates two subpopulations of the neuronal Rho<scp>GEF</scp> Kalirin‐7

Miller, Megan B.; Yan, Yan; Wu, Yi; Hao, Bing; Mains, Richard E.; Eipper, Betty A.

doi:10.1111/jnc.13749

Cited by 12 publications

(33 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The emission spectra for HEK293 cells transfected with the Rac1 biosensor and selected TGEF1 constructs are shown in Figure 4A. Transfection of increasing amounts of wild-type (WT) TGEF1 yielded a dose-dependent increase in Rac1 biosensor FRET, as observed with similar KALIRIN GEF1 constructs (67,73).…”

Section: Disease-associated Variants In the Trio Gef1 Domain Reduce Its Activitymentioning

confidence: 73%

“…The truncation mutants (R1276stop; K1918stop) were treated as equivalent to the addition of no exogenous GEF. Some non-case-associated variants (I1329F, I1329S, in an additional lane of human cortical extract; molecular weights of standards (kDa) are indicated (67). (B) qPCR averaged across 8 assays of human fetal and adult brain cDNA; primer locations are indicated (see Fig.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Neurodevelopmental disease-associated de novo mutations and rare sequence variants affect TRIO GDP/GTP exchange factor activity

Katrancha

Zhu

et al. 2017

Human Molecular Genetics

Self Cite

View full text Add to dashboard Cite

Bipolar disorder, schizophrenia, autism and intellectual disability are complex neurodevelopmental disorders, debilitating millions of people. Therapeutic progress is limited by poor understanding of underlying molecular pathways. Using a targeted search, we identified an enrichment of de novo mutations in the gene encoding the 330-kDa triple functional domain (TRIO) protein associated with neurodevelopmental disorders. By generating multiple TRIO antibodies, we show that the smaller TRIO9 isoform is the major brain protein product, and its levels decrease after birth. TRIO9 contains two guanine nucleotide exchange factor (GEF) domains with distinct specificities: GEF1 activates both Rac1 and RhoG; GEF2 activates RhoA. To understand the impact of disease-associated de novo mutations and other rare sequence variants on TRIO function, we utilized two FRET-based biosensors: a Rac1 biosensor to study mutations in TRIO (T)GEF1, and a RhoA biosensor to study mutations in TGEF2. We discovered that one autism-associated de novo mutation in TGEF1 (K1431M), at the TGEF1/Rac1 interface, markedly decreased its overall activity toward Rac1. A schizophrenia-associated rare sequence variant in TGEF1 (F1538Intron) was substantially less active, normalized to protein level and expressed poorly. Overall, mutations in TGEF1 decreased GEF1 activity toward Rac1. One bipolar disorder-associated rare variant (M2145T) in TGEF2 impaired inhibition by the TGEF2 pleckstrin-homology domain, resulting in dramatically increased TGEF2 activity. Overall, genetic damage to both TGEF domains altered TRIO catalytic activity, decreasing TGEF1 activity and increasing TGEF2 activity. Importantly, both GEF changes are expected to decrease neurite outgrowth, perhaps consistent with their association with neurodevelopmental disorders.

show abstract

Section: Disease-associated Variants In the Trio Gef1 Domain Reduce Its Activitymentioning

confidence: 73%

Section: Resultsmentioning

confidence: 99%

Neurodevelopmental disease-associated de novo mutations and rare sequence variants affect TRIO GDP/GTP exchange factor activity

Katrancha

Zhu

et al. 2017

Human Molecular Genetics

Self Cite

View full text Add to dashboard Cite

show abstract

“…Kal7 expression is largely limited to neurons, with Kal7 concentrated at the PSD 11, 12 . Excitatory glutamatergic neurons predominate in the PFC while inhibitory GABAergic neurons predominate in the NAc 39, 44, 52 .…”

Section: Resultsmentioning

confidence: 99%

“…While Kal7 is largely particulate, much of the Kal9/Kal12 is soluble 11, 22 . Since a difference in subcellular localization could result in exposure to different protein kinases, we asked whether the extent of phosphorylation at sites common to Kal7, Kal9 and Kal12 differed.…”

Section: Resultsmentioning

confidence: 99%

Brain Region and Isoform-Specific Phosphorylation Alters Kalirin SH2 Domain Interaction Sites and Calpain Sensitivity

Miller¹,

Yan²,

Machida³

et al. 2017

ACS Chem. Neurosci.

Self Cite

View full text Add to dashboard Cite

Kalirin7 (Kal7), a postsynaptic Rho GDP/GTP exchange factor (RhoGEF), plays a crucial role in long term potentiation and in the effects of cocaine on behavior and spine morphology. The KALRN gene has been linked to schizophrenia and other disorders of synaptic function. Mass spectrometry was used to quantify phosphorylation at 26 sites in Kal7 from individual adult rat nucleus accumbens and prefrontal cortex before and after exposure to acute or chronic cocaine. Region- and isoform-specific phosphorylation was observed along with region-specific effects of cocaine on Kal7 phosphorylation. Evaluation of the functional significance of multi-site phosphorylation in a complex protein like Kalirin is difficult. With the identification of five tyrosine phosphorylation (pY) sites, a panel of 71 SH2 domains was screened, identifying subsets that interacted with multiple pY sites in Kal7. In addition to this type of reversible interaction, endoproteolytic cleavage by calpain plays an essential role in long-term potentiation. Calpain cleaved Kal7 at two sites, separating the N-terminal domain, which affects spine length, and the PDZ binding motif from the GEF domain. Mutations preventing phosphorylation did not affect calpain sensitivity or GEF activity; phosphomimetic mutations at specific sites altered protein stability, increased calpain sensitivity and reduced GEF activity.

show abstract

“…The mammalian Kalirin ( Kalrn ) gene locus gives rise to several isoforms which have diverse and sometimes antagonistic effects on dendritogenesis. The Kalrn gene can code for a protein with a lipid binding motif, several tandem spectrin homology domains and additional protein-protein interaction domains like SH3 domain commonly found in members of signaling pathways (McPherson et al, 2002, 2004; Vishwanatha et al, 2012; Miller et al, 2017). The functional differences between isoforms are thought to arise from the combinations of protein domains retained in the splice isoforms.…”

Section: Introductionmentioning

confidence: 99%

A Novel Long Non-coding RNA, durga Modulates Dendrite Density and Expression of kalirin in Zebrafish

Sarangdhar

Chaubey

Bhatt

et al. 2017

Front. Mol. Neurosci.

View full text Add to dashboard Cite

Kalirin, a key player in axonal development, nerve growth and synaptic re-modeling, is implicated in many pathological conditions like schizophrenia and autism-spectrum disorders. Alternative promoters and splicing lead to functionally distinct isoforms, but the post-transcriptional regulation of Kalirin has not been studied. Here, we report a novel non-coding RNA, which we name durga, arising from the first exon of kalirin a (kalrna) in the antisense orientation in zebrafish. The kalrna and durga transcripts are barely detectable during early development, but steadily increase by 24 hours post-fertilization (hpf) as the brain develops. Over-expression of durga in the zebrafish embryo led to an increase in kalrna expression. The morphology of the neurons cultured from durga injected embryos had significantly fewer and shorter dendrites. Although durga has no apparent sequence homolog in mammals, based on gene synteny, we found a non-coding RNA arising from the 5′ end of the human Kalrn gene and expressed in the human neuronal cell line, SH-SY5Y. We propose that the zebrafish lncRNA durga maintains dendritic length and density through regulation of kalrna expression and this may have further implications in mammalian systems.

show abstract

Alternate promoter usage generates two subpopulations of the neuronal RhoGEF Kalirin‐7

Cited by 12 publications

References 67 publications

Neurodevelopmental disease-associated de novo mutations and rare sequence variants affect TRIO GDP/GTP exchange factor activity

Neurodevelopmental disease-associated de novo mutations and rare sequence variants affect TRIO GDP/GTP exchange factor activity

Brain Region and Isoform-Specific Phosphorylation Alters Kalirin SH2 Domain Interaction Sites and Calpain Sensitivity

A Novel Long Non-coding RNA, durga Modulates Dendrite Density and Expression of kalirin in Zebrafish

Contact Info

Product

Resources

About