Abstract
A set of nuclear mutants of C. reinhardtii were identified that specifically lack translation of the chloroplast-encoded psbA mRNA, which encodes the photosystem II reaction center polypeptide D1. Two of these mutants are deficient in the 47-kD member (RB47) of the psbA RNA-binding complex, which has previously been identified both genetically and biochemically as a putative translational activator of the chloroplast psbA mRNA. RB47 is a member of the poly(A)-binding protein family, and binds with high affinity and specificity to the 5' untranslated region of the psbA mRNA. The results presented here confirm RB47's role as a message-specific translational activator in the chloroplast, and bring together genetic and biochemical data to form a cohesive model for light- activated translational regulation in the chloroplast.
Publication types
-
Research Support, Non-U.S. Gov't
-
Research Support, U.S. Gov't, Non-P.H.S.
MeSH terms
-
Animals
-
Cell Nucleus / metabolism
-
Chlamydomonas reinhardtii / genetics*
-
Chlamydomonas reinhardtii / metabolism*
-
Chlamydomonas reinhardtii / radiation effects
-
Chloroplasts / metabolism
-
Chloroplasts / radiation effects
-
Gene Expression
-
Light
-
Models, Biological
-
Mutagenesis, Insertional
-
Mutation
-
Photosynthetic Reaction Center Complex Proteins / genetics*
-
Photosystem II Protein Complex
-
Poly(A)-Binding Proteins
-
Protein Biosynthesis
-
Protozoan Proteins / genetics
-
Protozoan Proteins / metabolism
-
RNA, Messenger / genetics*
-
RNA, Messenger / metabolism
-
RNA, Protozoan / genetics
-
RNA, Protozoan / metabolism
-
RNA-Binding Proteins / metabolism*
Substances
-
Photosynthetic Reaction Center Complex Proteins
-
Photosystem II Protein Complex
-
Poly(A)-Binding Proteins
-
Protozoan Proteins
-
RNA, Messenger
-
RNA, Protozoan
-
RNA-Binding Proteins