title: Regulation of Shootin1 Gene Expression Involves NGF-induced Alternative Splicing during Neuronal Differentiation of PC12 Cells.
abstract: Shootin1 is a protein involved in neuronal polarization, and has been shown to be a key molecule for the positive/negative feedback loop for axon induction required during neuronal symmetry breaking. To better understand the molecular basis of shootin1 dynamics, we analysed the regulatory pathways and the expressional status of shootin1 gene during NGF-induced neuronal differentiation. We demonstrated that the isoform-1 and isoform-2 of shootin1 is differentially expressed during neuronal differentiation. By blocking individual downstream pathways of NGF signalling, we found that PI3K/Akt pathway plays a major role in the expression of shootin1 isoform-2. Western blot and RT-PCR results showed that the isoform-1 of shootin1 is constitutively expressed, while the isoform-2 is expressed in a manner that is strictly dependent on NGF-stimulation. Isoform-specific RT-PCR results demonstrated that the differential expression of the isoform-1 and isoform-2 of shootin1 is a consequence of alternative splicing of shootin1 pre-mRNA, in response to NGF-signalling. Collectively these findings provide the first information on the molecular mechanisms regulating the expression of shootin1 gene and represent the first example of NGF-induced alternative splicing process that has a regulatory role in neuritogenesis.
authors.affiliation: Department of Medical Biology &Genetics, Faculty of Medicine, Gazi University, 06560 Ankara, Turkey.
authors.forename: Volkan
authors.initials: V
authors.lastname: Ergin
authors.affiliation: UNAM - Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara, Turkey.
authors.forename: Mutlu
authors.initials: M
authors.lastname: Erdogan
authors.affiliation: Department of Medical Biology &Genetics, Faculty of Medicine, Gazi University, 06560 Ankara, Turkey.
authors.forename: Adnan
authors.initials: A
authors.lastname: Menevse
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D023061:Gene Order; D020932:Nerve Growth Factor / Q000378:metabolism* / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000235:genetics*; D016501:Neurites / Q000378:metabolism; D009474:Neurons / Q000166:cytology* / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D020033:Protein Isoforms; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats
chemical_list: D020932:Nerve Growth Factor; D009419:Nerve Tissue Proteins; D019869:Phosphatidylinositol 3-Kinases; D020033:Protein Isoforms; D051057:Proto-Oncogene Proteins c-akt; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C514975:Shtn1 protein, rat