Functional association between promoter structure and transcript alternative splicing

Functional association between promoter structure and transcript alternative splicing

^*Laboratorio de Fisiología y Biología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Ciudad Universitaria, Pabellón II, (1428) Buenos Aires, Argentina; and ^†International Centre for Genetic Engineering and Biotechnology, Trieste, Italy

Communicated by Cesar Milstein, Medical Research Council, Cambridge, United Kingdom (received for review June 30, 1997)

Abstract

It has been assumed that constitutive and regulated splicing of RNA polymerase II transcripts depends exclusively on signals present in the RNA molecule. Here we show that changes in promoter structure strongly affect splice site selection. We investigated the splicing of the ED I exon, which encodes a facultative type III repeat of fibronectin, whose inclusion is regulated during development and in proliferative processes. We used an alternative splicing assay combined with promoter swapping to demonstrate that the extent of ED I splicing is dependent on the promoter structure from which the transcript originated and that this regulation is independent of the promoter strength. Thus, these results provide the first evidence for coupling between alternative splicing and promoter-specific transcription, which agrees with recent cytological and biochemical evidence of coordination between splicing and transcription.

Footnotes

↵ ‡ To whom reprint requests should be addressed. e-mail: ark{at}bg.fcen.uba.ar.
ABBREVIATIONS:

FN,

fibronectin;

MMTV,

mouse mammary tumor virus;

CMV,

cytomegalovirus, β-gal, β-galactosidase;

RT,

reverse transcription;

CTD,

C-terminal domain;

CRE,

cyclic AMP response element;

SE,

splicing enhancer;

SR,

serine–arginine-rich;

pol I,

II, and III, RNA polymerases I, II, and III