Biology:Kalirin

From HandWiki
Short description: Protein-coding gene in the species Homo sapiens


A representation of the 3D structure of the protein myoglobin showing turquoise α-helices.
Generic protein structure example


Kalirin, also known as Huntingtin-associated protein-interacting protein (HAPIP), protein duo (DUO), or serine/threonine-protein kinase with Dbl- and pleckstrin homology domain, is a protein that in humans is encoded by the KALRN gene.[1][2] Kalirin was first identified in 1997 as a protein interacting with huntingtin-associated protein 1.[1] Is also known to play an important role in nerve growth and axonal development.[3]

Kalirin is a member of the Dbl family of proteins and is a Rho guanine nucleotide exchange factor.

It is named after the multiple-handed Hindu goddess Kali for its ability to interact with numerous other proteins. Kalirin's other name, DUO, comes from the fact that it is 98% identical to rat DUO protein and 80.6% identical to a human protein named TRIO. Unlike TRIO, which is expressed in numerous tissues, Kalirin isoforms are mainly found in the brain.

Clinical significance

Several isoforms of Kalirin are produced through alternative splicing.[4] One of the isoforms, Kalirin-7, was found to be necessary for the remodeling of synapses in mature cortical neurons and is thought to be important in the development of schizophrenia,[5][6][7][8] as demonstrated by adolescent development of schizophrenia-like symptoms in kalirin knockout mice.[9] Alzheimer's disease may also be linked to kalirin-7.[8][10][11]

The KALRN gene, has been linked to multiple neurological disorders both through large exome and genome sequencing efforts, as well as post mortem and clinical studies.

Several mutations within KALRN have been linked to neurological disease. In autism spectrum disorder, a frameshift mutation was found[12][13] that is likely to lead to transcript decay, and heterozygosity. Another, found within the second GEF domain, is predicted to be highly deleterious to RhoA-GEF activity and likely affects the function of kalirin9 and 12 isoforms early in neuronal development.[14] A patient harboring a homozygous mutation in kalirin's spectrin repeat domain was found to have severe intellectual disability,[15] and both truncating and missense mutations have been identified in patients with developmental delay.[16] Several intronic variants have been associated with addiction and were found to alter the function of brain regions responsible for reward anticipation.[17] This link to addiction is supported by animal models, where loss of kalirin results in altered cocaine self-administration and synaptic and expression changes in response to cocaine.[18][19][20] Perhaps the most compelling genetic links are between kalirin and schizophrenia. Numerous missense mutations in KALRN have been identified in exome sequencing studies of schizophrenia cohorts [21] that are predicted to be deleterious to protein function.

Neuronal studies have provided insight into the mechanisms of some missense mutations, particularly within the GEF domains of KALRN. A mutation found within the Rac-GEF domain was found to induce strong reductions in Rac activation, neuronal branching, and spine density.[22] These effects were mirrored by mutations in the RhoA-GEF domain, producing similar neuronal deficits, but by promoting RhoA-GEF activity.[23] In addition to exome sequencing, post-mortem studies have consistently found alterations in kalirin transcript levels within the brain [24][25] further supporting a role for kalirin in the etiology of schizophrenia.

In addition to neurodevelopmental disorders, kalirin has been found to be underexpressed in the post-mortem Alzheimer's brain.[11][10] This loss of kalirin expression was recapitulated in animal models of Alzheimer's disease.[26][27] Moreover, introduction of kalirin7 into culture [28] or animal models [27] of Alzheimer's disease was able to rescue synaptic and behavioral deficits, suggesting an important role for kalirin in regulating synapse loss and cognitive impairment in Alzheimer's disease.

Function

The majority of kalirin's effects are induced through its catalytic GEF domain signaling. By promoting the release of GDP from Rac and RhoA, it acts as an activator of GTPase signaling within the cell.[29] Although able to activate Rac and RhoA, much of its activity in regulating neuronal morphology has been attributed to Rac-PAK pathway activation.[30] kalirin has found been found to exert control over dendritic arborization,[31] axonal growth,[29][32] dendritic spine formation [33] and synaptic activity [34][9] and plasticity.[34][35][36][37] These effects are regulated by protein-protein interactions and post-translational modifications within the non-catalytic domains, and have been shown to exert control over kalirin subcellular targeting and activation.[34][33][38]

Kalirin has been found to play a critical role in synaptic activity and plasticity. Loss of KALRN results in decreased nMDAr and AMPAr-mediated mEPSC,[9] and kalirin7 knockout animals show strong deficits in NMDAr mediated long-term potentiation [9][36] and long term depression.[35] This may be linked to the ability to regulate RAC-PAK signaling and actin dynamics, which in turn can regulate the size and density of dendritic spines.[9] Within dendritic spines, kalirin interacts with multiple disease-related proteins to regulate synapse strength. It directly interacts with the schizophrenia risk factor DISC1 that can act to suppress kalirin function within the spine.[39] Furthermore, kalirin7 directly interacts with the GluN2B subunit of the NMDA receptor [36] and PSD95 [40] within the post-synaptic density.

The importance of KALRN in neurodevelopment is supported by knockout animal models that display profound deficiencies in multiple behavioral tasks. Kalirin knockout animals display reduced GEF activity,[9] dendritic arborization and spine density.[41] These deficits may be linked to the observed reductions in prepulse inhibition, sociability and increased locomotor activity. Notably, loss of kalirin results in deficits in working memory, but not reference memory.[9][42] The generation of a kalirin7 specific knockout animal model revealed similar deficits in spine density,[42][43] suggesting a central role of kalirin7 in regulating neuronal connectivity. Both full and kalirin7 specific knockout animals show decreased anxiety-like behavior and impaired contextual fear learning.[43][44][6]

Expression

Multiple isoforms, arising from alternate splicing and promoter usage, display varying tissue and developmental expression.[45][46] Control over kalirin expression is exerted through the use of alternate promoters which produce alternate start sites and restrict expression to specific neuronal subpopulations, and alter kalirin activity within neurons.[47][48] During early development, the long kalirin9 and 12 isoforms are predominant in the brain. These isoforms contain both a Rac and a RhoA selective GEF domain, and control axonal growth and dendritic branching. Kalirin9 and 12 are also expressed ubiquitously throughout the body [49] and have functions outside the brain. However, during neurodevelopment, the kalirin7 isoform is preferentially expressed during periods of synaptogenesis, and this isoform displays highly restricted cortical expression.[49][50] Kalirin7 expresses only the N-terminal domains, including the Rac-GEF domain along with a c-terminal PDZ-binding domain that strongly targets kalirin7 to the post-synaptic density.[40] It is likely this subcellular distribution is vital to kalirin7 function, as this isoform exerts control dendritic spine density and synaptic plasticity. It is likely that mutations that result in deregulation of kalirin function within the brain is responsible for the role of kalirin within multiple neurological disorders.

Notes

References

  1. ↑ 1.0 1.1 "Huntingtin-associated protein 1 (HAP1) binds to a Trio-like polypeptide, with a rac1 guanine nucleotide exchange factor domain". Human Molecular Genetics 6 (9): 1519–25. September 1997. doi:10.1093/hmg/6.9.1519. PMID 9285789. 
  2. ↑ "Duet is a novel serine/threonine kinase with Dbl-Homology (DH) and Pleckstrin-Homology (PH) domains". Gene 227 (2): 249–55. February 1999. doi:10.1016/S0378-1119(98)00605-2. PMID 10023074. 
  3. ↑ "Critical role for Kalirin in nerve growth factor signaling through TrkA". Molecular and Cellular Biology 25 (12): 5106–18. June 2005. doi:10.1128/MCB.25.12.5106-5118.2005. PMID 15923627. 
  4. ↑ "Genomic organization and differential expression of Kalirin isoforms". Gene 284 (1–2): 41–51. February 2002. doi:10.1016/S0378-1119(02)00386-4. PMID 11891045. 
  5. ↑ "Kalirin-7 controls activity-dependent structural and functional plasticity of dendritic spines". Neuron 56 (4): 640–56. November 2007. doi:10.1016/j.neuron.2007.10.005. PMID 18031682. 
  6. ↑ 6.0 6.1 "Kalirin-7 is required for synaptic structure and function". The Journal of Neuroscience 28 (47): 12368–82. November 2008. doi:10.1523/JNEUROSCI.4269-08.2008. PMID 19020030. 
  7. ↑ "Kalirin-7: linking spine plasticity and behavior". The Journal of Neuroscience 29 (17): 5367–9. April 2009. doi:10.1523/JNEUROSCI.0235-09.2009. PMID 19403804. 
  8. ↑ 8.0 8.1 "Dendritic spine dynamics--a key role for kalirin-7". Trends in Neurosciences 31 (8): 419–27. August 2008. doi:10.1016/j.tins.2008.06.001. PMID 18597863. 
  9. ↑ 9.0 9.1 9.2 9.3 9.4 9.5 9.6 "Kalirin regulates cortical spine morphogenesis and disease-related behavioral phenotypes". Proceedings of the National Academy of Sciences of the United States of America 106 (31): 13058–63. August 2009. doi:10.1073/pnas.0904636106. PMID 19625617. Bibcode: 2009PNAS..10613058C. 
  10. ↑ 10.0 10.1 "Under-expression of Kalirin-7 Increases iNOS activity in cultured cells and correlates to elevated iNOS activity in Alzheimer's disease hippocampus". Journal of Alzheimer's Disease 12 (3): 271–81. November 2007. doi:10.3233/jad-2007-12309. PMID 18057561. 
  11. ↑ 11.0 11.1 "Kalirin is under-expressed in Alzheimer's disease hippocampus". Journal of Alzheimer's Disease 11 (3): 385–97. June 2007. doi:10.3233/jad-2007-11314. PMID 17851188. 
  12. ↑ Lek, Monkol; Diab, Nicholas (2019-07-15). "Faculty Opinions recommendation of Large-scale exome sequencing study implicates both developmental and functional changes in the neurobiology of autism.". Faculty Opinions. doi:10.3410/f.734542901.793562583. 
  13. ↑ "Faculty Opinions recommendation of Large-scale exome sequencing study implicates both developmental and functional changes in the neurobiology of autism.". Faculty Opinions. 2019-07-15. doi:10.3410/f.734542901.793562583. 
  14. ↑ "Both rare and common genetic variants contribute to autism in the Faroe Islands". npj Genomic Medicine 4: 1. 2018-07-06. doi:10.1038/s41525-018-0075-2. PMID 30675382. 
  15. ↑ "Exome sequencing discloses KALRN homozygous variant as likely cause of intellectual disability and short stature in a consanguineous pedigree". Human Genomics 10 (1): 26. July 2016. doi:10.1186/s40246-016-0082-2. PMID 27421267. 
  16. ↑ "Prevalence and Architecture of De Novo Mutations in Developmental Disorders". Obstetrical & Gynecological Survey 72 (6): 340–341. June 2017. doi:10.1097/ogx.0000000000000460. ISSN 0029-7828. http://eprints.whiterose.ac.uk/141471/1/Prevalence%20and%20architecture%20of%20de%20novo%20mutations%20in%20developmental%20disorders.pdf. 
  17. ↑ "Mouse and Human Genetic Analyses Associate Kalirin with Ventral Striatal Activation during Impulsivity and with Alcohol Misuse". Frontiers in Genetics 7: 52. 2016-04-07. doi:10.3389/fgene.2016.00052. PMID 27092175. 
  18. ↑ "Constitutive knockout of kalirin-7 leads to increased rates of cocaine self-administration". Molecular Pharmacology 84 (4): 582–90. October 2013. doi:10.1124/mol.113.087106. PMID 23894151. 
  19. ↑ "Correction: Wang et al., Kalirin-7 Mediates Cocaine-Induced AMPA Receptor and Spine Plasticity, Enabling Incentive Sensitization". Journal of Neuroscience 34 (2): 688. 2014-01-08. doi:10.1523/jneurosci.4822-13.2014. ISSN 0270-6474. 
  20. ↑ "Behavioral and morphological responses to cocaine require kalirin7". Biological Psychiatry 68 (3): 249–55. August 2010. doi:10.1016/j.biopsych.2010.03.024. PMID 20452575. 
  21. ↑ "Faculty Opinions recommendation of A polygenic burden of rare disruptive mutations in schizophrenia.". Faculty Opinions. 2014-03-07. doi:10.3410/f.718252264.793491785. 
  22. ↑ "A sequence variant in human KALRN impairs protein function and coincides with reduced cortical thickness". Nature Communications 5 (1): 4858. September 2014. doi:10.1038/ncomms5858. PMID 25224588. Bibcode: 2014NatCo...5.4858R. 
  23. ↑ "Resequencing and association analysis of the KALRN and EPHB1 genes and their contribution to schizophrenia susceptibility". Schizophrenia Bulletin 38 (3): 552–60. May 2012. doi:10.1093/schbul/sbq118. PMID 21041834. 
  24. ↑ "Molecular profiles of schizophrenia in the CNS at different stages of illness". Brain Research 1239: 235–48. November 2008. doi:10.1016/j.brainres.2008.08.023. PMID 18778695. 
  25. ↑ "Molecular mechanisms contributing to dendritic spine alterations in the prefrontal cortex of subjects with schizophrenia". Molecular Psychiatry 11 (6): 557–66. June 2006. doi:10.1038/sj.mp.4001792. PMID 16402129. 
  26. ↑ "Faculty Opinions recommendation of Changes in the Synaptic Proteome in Tauopathy and Rescue of Tau-Induced Synapse Loss by C1q Antibodies.". Faculty Opinions. 2018-12-19. doi:10.3410/f.734327820.793554446. 
  27. ↑ 27.0 27.1 "The transcription factor XBP1s restores hippocampal synaptic plasticity and memory by control of the Kalirin-7 pathway in Alzheimer model". Molecular Psychiatry 22 (11): 1562–1575. November 2017. doi:10.1038/mp.2016.152. PMID 27646263. 
  28. ↑ "Kalirin-7 prevents dendritic spine dysgenesis induced by amyloid beta-derived oligomers". The European Journal of Neuroscience 49 (9): 1091–1101. May 2019. doi:10.1111/ejn.14311. PMID 30565792. 
  29. ↑ 29.0 29.1 "Distinct roles for the two Rho GDP/GTP exchange factor domains of kalirin in regulation of neurite growth and neuronal morphology". The Journal of Neuroscience 21 (21): 8426–34. November 2001. doi:10.1523/jneurosci.21-21-08426.2001. PMID 11606631. 
  30. ↑ "Rapid modulation of spine morphology by the 5-HT2A serotonin receptor through kalirin-7 signaling". Proceedings of the National Academy of Sciences of the United States of America 106 (46): 19575–80. November 2009. doi:10.1073/pnas.0905884106. PMID 19889983. Bibcode: 2009PNAS..10619575J. 
  31. ↑ "Kalirin-9 and Kalirin-12 Play Essential Roles in Dendritic Outgrowth and Branching". Cerebral Cortex 25 (10): 3487–501. October 2015. doi:10.1093/cercor/bhu182. PMID 25146373. 
  32. ↑ "Kalirin Dbl-homology guanine nucleotide exchange factor 1 domain initiates new axon outgrowths via RhoG-mediated mechanisms". The Journal of Neuroscience 22 (16): 6980–90. August 2002. doi:10.1523/jneurosci.22-16-06980.2002. PMID 12177196. 
  33. ↑ 33.0 33.1 "Kalirin-7 controls activity-dependent structural and functional plasticity of dendritic spines". Neuron 56 (4): 640–56. November 2007. doi:10.1016/j.neuron.2007.10.005. PMID 18031682. 
  34. ↑ 34.0 34.1 34.2 "Kalirin and Trio proteins serve critical roles in excitatory synaptic transmission and LTP". Proceedings of the National Academy of Sciences of the United States of America 113 (8): 2264–9. February 2016. doi:10.1073/pnas.1600179113. PMID 26858404. Bibcode: 2016PNAS..113.2264H. 
  35. ↑ 35.0 35.1 "Kalirin-7 is necessary for normal NMDA receptor-dependent synaptic plasticity". BMC Neuroscience 12 (1): 126. December 2011. doi:10.1186/1471-2202-12-126. PMID 22182308. 
  36. ↑ 36.0 36.1 36.2 "Kalirin binds the NR2B subunit of the NMDA receptor, altering its synaptic localization and function". The Journal of Neuroscience 31 (35): 12554–65. August 2011. doi:10.1523/jneurosci.3143-11.2011. PMID 21880917. 
  37. ↑ "Using Kalirin conditional knockout mice to distinguish its role in dopamine receptor mediated behaviors". BMC Neuroscience 18 (1): 45. May 2017. doi:10.1186/s12868-017-0363-2. PMID 28535798. 
  38. ↑ "Synaptic Kalirin-7 and Trio Interactomes Reveal a GEF Protein-Dependent Neuroligin-1 Mechanism of Action". Cell Reports 29 (10): 2944–2952.e5. December 2019. doi:10.1016/j.celrep.2019.10.115. PMID 31801062. 
  39. ↑ "Disrupted-in-Schizophrenia 1 (DISC1) regulates spines of the glutamate synapse via Rac1". Nature Neuroscience 13 (3): 327–32. March 2010. doi:10.1038/nn.2487. PMID 20139976. 
  40. ↑ 40.0 40.1 "The neuronal Rho-GEF Kalirin-7 interacts with PDZ domain-containing proteins and regulates dendritic morphogenesis". Neuron 29 (1): 229–42. January 2001. doi:10.1016/s0896-6273(01)00193-3. PMID 11182094. 
  41. ↑ "Kalirin loss results in cortical morphological alterations". Molecular and Cellular Neurosciences 43 (1): 81–9. January 2010. doi:10.1016/j.mcn.2009.09.006. PMID 19800004. 
  42. ↑ 42.0 42.1 "Long-term perturbation of spine plasticity results in distinct impairments of cognitive function". Journal of Neurochemistry 123 (5): 781–9. December 2012. doi:10.1111/j.1471-4159.2012.07899.x. PMID 22862288. 
  43. ↑ 43.0 43.1 "Hippocampal phenotypes in kalirin-deficient mice". Molecular and Cellular Neurosciences 46 (1): 45–54. January 2011. doi:10.1016/j.mcn.2010.08.005. PMID 20708080. 
  44. ↑ "Kalrn plays key roles within and outside of the nervous system". BMC Neuroscience 13 (1): 136. November 2012. doi:10.1186/1471-2202-13-136. PMID 23116210. 
  45. ↑ "Isoforms of kalirin, a neuronal Dbl family member, generated through use of different 5'- and 3'-ends along with an internal translational initiation site". The Journal of Biological Chemistry 275 (25): 19324–33. June 2000. doi:10.1074/jbc.m000676200. PMID 10777487. 
  46. ↑ "Genomic organization and differential expression of Kalirin isoforms". Gene 284 (1–2): 41–51. February 2002. doi:10.1016/s0378-1119(02)00386-4. PMID 11891045. 
  47. ↑ "Kalrn promoter usage and isoform expression respond to chronic cocaine exposure". BMC Neuroscience 12 (1): 20. February 2011. doi:10.1186/1471-2202-12-20. PMID 21329509. 
  48. ↑ "An N-terminal Amphipathic Helix Binds Phosphoinositides and Enhances Kalirin Sec14 Domain-mediated Membrane Interactions". The Journal of Biological Chemistry 290 (21): 13541–55. May 2015. doi:10.1074/jbc.m115.636746. PMID 25861993. 
  49. ↑ 49.0 49.1 "Kalirin, a GDP/GTP exchange factor of the Dbl family, is localized to nerve, muscle, and endocrine tissue during embryonic rat development". The Journal of Histochemistry and Cytochemistry 49 (7): 833–44. July 2001. doi:10.1177/002215540104900704. PMID 11410608. 
  50. ↑ "Kalirin, a key player in synapse formation, is implicated in human diseases". Neural Plasticity 2012: 728161. 2012. doi:10.1155/2012/728161. PMID 22548195. 

External links



Retrieved from "https://handwiki.org/wiki/index.php?title=Biology:Kalirin&oldid=3575445"