title: Human low molecular weight neurofilament (NFL) mRNA interacts with a predicted p190RhoGEF homologue (RGNEF) in humans.
abstract: In the mouse, p190RhoGEF is a low molecular weight neurofilament (NFL) mRNA stability factor that is involved in NF aggregate formation in neurons. A human homologue of this protein has not been described. Our objective was to identify a human homologue of p190RhoGEF, and to determine its interaction with human NFL mRNA. We used sequence homology searches to predict a human homologue (RGNEF), and RT-PCR to determine the expression of mRNA in ALS and neuropathologically normal control tissues. Gel shift assays determined the interaction of RGNEF with human NFL mRNA in vitro, while IP-RT-PCR and gel shift assays were used to confirm the interaction in tissue lysates. We determined that RGNEF is a human homologue of p190RhoGEF, and that its RNA is expressed in both brain and spinal cord. While RGNEF and NFL mRNA interact directly in vitro, interestingly they only appear to interact in ALS lysates and not in controls. These data add another player to the family of NFL mRNA stability regulators, and raise the intriguing possibility that the mechanism by which p190RhoGEF contributes to murine neuronal NF aggregate formation may be important to human ALS NF aggregate formation.
authors.affiliation: Robarts Research Institute, London, Ontario, Canada.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Volkening
authors.forename: Cheryl
authors.initials: C
authors.lastname: Leystra-Lantz
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Strong
mesh_terms: D000595:Amino Acid Sequence; D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D002490:Central Nervous System / Q000473:pathology / Q000502:physiology; D003001:Cloning, Molecular; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D016900:Neurofilament Proteins / Q000378:metabolism*; D020871:RNA Stability; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020666:ras-GRF1 / Q000235:genetics* / Q000378:metabolism*
chemical_list: C551174:ARHGEF28 protein, human; D020662:Guanine Nucleotide Exchange Factors; D016900:Neurofilament Proteins; D012333:RNA, Messenger; C513037:Rasgrf1 protein, mouse; C044882:neurofilament protein L; D020666:ras-GRF1