Student Theses and Dissertations

Date of Award

1996

Document Type

Thesis

Degree Name

Doctor of Philosophy (PhD)

RU Laboratory

Darnell Robert Laboratory

Abstract

We have identified a cDNA encoding a protein that is recognized by sera from (7/7) patients with paraneoplastic opsoclonus-myoclonus ataxia (POMA). The gene, Nova-I, encodes a novel nuclear RNA binding protein (RBP) that is extremely highly conserved (99% amino acid identity) between human and mouse. Nova-I is normally expressed only within neurons of the central nervous system (eNS). Both Nova-I protein and RNA are restricted to a subset of eNS neurons which correlate with the specific neurologic symptoms seen in POMA. Nova-I contains three KH type RNA binding motifs, and binds RNA in vitro via these KH motifs. Mutations within the core of the KH motif abolish specific RNA binding. Utilizing RNA selection, we have identified an in vitro RNA ligand for Nova-I consisting of three UeAUY repeats in the loop of a stem loop structure. We have identified a similar sequence upstream of the alternatively spliced exons (3A and 3B) of the Glycine receptor a2A (glyRa2A), and downstream of the alternatively spliced exon H of Nova-I, and demonstrate that Nova-I binds these RNAs with high affinity (Kd .... 2 nM). We have also shown that Nov a-I binds both the glyRa2A and Nova-I pre-mRNAs in vivo. Nova-I binding to the target sequence in the glyRa2A RNA in tissue culture cells stimulates splicing to exon 3A suggesting that Nova-I functions in regulating alternative splicing in mouse brain. Moreover, the demonstration that paraneoplastic antibodies can prevent Nova-I from binding to glyRa2A RNA in vitro suggests a potential mechanism for the neurologic symptoms of POMA.

Comments

A thesis presented to the faculty of The Rockefeller University in partial fulfillment of the requirements for the degree of Doctor of Philosophy

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