title: Expression of cyr61, a growth factor-inducible immediate-early gene.
abstract: A set of immediate-early genes that are rapidly activated by serum or purified platelet-derived growth factor in mouse 3T3 fibroblasts has been previously identified. Among these genes, several are related to known or putative transcription factors and growth factors, supporting the notion that some of these genes encode regulatory molecules important to cell growth. We show here that a member of this set of genes, cyr61 (originally identified by its cDNA 3CH61), encodes a 379-amino-acid polypeptide rich in cysteine residues. cyr61 can be induced through protein kinase C-dependent and -independent pathways. Unlike many immediate-early genes that are transiently expressed, the cyr61 mRNA is accumulated from the G0/G1 transition through mid-G1. This expression pattern is due to persistent transcription, while the mRNA is rapidly turned over during the G0/G1 transition and in mid-G1 at the same rate. In logarithmically growing cells, the cyr61 mRNA level is constant throughout the cell cycle. Cyr61 contains an N-terminal secretory signal sequence; however, it is not detected in the culture medium by immunoprecipitation. Cyr61 is synthesized maximally at 1 to 2 h after serum stimulation and has a short half-life within the cell.
authors.affiliation: Department of Genetics, University of Illinois College of Medicine, Chicago 60612.
authors.forename: T P
authors.initials: TP
authors.lastname: O'Brien
authors.forename: G P
authors.initials: GP
authors.lastname: Yang
authors.forename: L
authors.initials: L
authors.lastname: Sanders
authors.forename: L F
authors.initials: LF
authors.lastname: Lau
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002455:Cell Division; D002460:Cell Line; D002478:Cells, Cultured; D003470:Culture Media; D055515:Cysteine-Rich Protein 61; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D015870:Gene Expression; D005796:Genes / Q000187:drug effects; D006133:Growth Substances / Q000235:genetics*; D006801:Humans; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D051379:Mice; D008969:Molecular Sequence Data; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D015183:Restriction Mapping; D014158:Transcription, Genetic
chemical_list: C501848:CCN1 protein, human; C491850:CCN1 protein, mouse; D003470:Culture Media; D055515:Cysteine-Rich Protein 61; D006133:Growth Substances; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D010982:Platelet-Derived Growth Factor; D011506:Proteins; D012333:RNA, Messenger; D004247:DNA