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Open Access Articles

Title

RNA target specificity of the embryonic cell fate determinant POS-1

PubMed ID

18952820

Authors

Brian M. Farley, University of Massachusetts Medical School
John M. Pagano, University of Massachusetts Medical School
Sean P. Ryder, University of Massachusetts Medical School

UMMS Affiliation

Department of Biochemistry and Molecular Pharmacology

Date

10-28-2008

Document Type

Article

Subjects

Animals; Base Sequence; Binding Sites; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Carrier Proteins; Consensus Sequence; Embryonic Development; RNA, Messenger; RNA-Binding Proteins; Untranslated Regions

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

Specification of Caenorhabditis elegans body axes and cell fates occurs prior to the activation of zygotic transcription. Several CCCH-type tandem zinc finger (TZF) proteins coordinate local activation of quiescent maternal mRNAs after fertilization, leading to asymmetric expression of factors required for patterning. The primary determinant of posterior fate is the TZF protein POS-1. Mutants of pos-1 are maternal effect lethal with a terminal phenotype that includes excess pharyngeal tissue and no endoderm or germline. Here, we delineate the consensus POS-1 recognition element (PRE) required for specific recognition of its target mRNAs. The PRE is necessary but not sufficient to pattern the expression of a reporter. The PRE is distinct from sequences recognized by related proteins from both mammals and nematodes, demonstrating that variants of this protein family can recognize divergent RNA sequences. The PRE is found within the 3' untranslated region of 227 maternal transcripts required for early development, including genes involved in endoderm and germline specification. The results enable prediction of novel targets that explain the pleiotropy of the pos-1 phenotype.