SLBP

This gene encodes a protein that binds to the stem-loop structure in replication-dependent histone mRNAs. Histone mRNAs do not contain introns or polyadenylation signals, and are processed by endonucleolytic cleavage. The stem-loop structure is essential for efficient processing but this structure also controls the transport, translation and stability of histone mRNAs. Expression of the protein is regulated during the cell cycle, increasing more than 10-fold during the latter part of G1. [provided by RefSeq]

Full Name

stem-loop binding protein

Function

RNA-binding protein involved in the histone pre-mRNA processing (PubMed:8957003, PubMed:9049306, PubMed:12588979, PubMed:19155325).
Binds the stem-loop structure of replication-dependent histone pre-mRNAs and contributes to efficient 3'-end processing by stabilizing the complex between histone pre-mRNA and U7 small nuclear ribonucleoprotein (snRNP), via the histone downstream element (HDE) (PubMed:8957003, PubMed:9049306, PubMed:12588979, PubMed:19155325).
Plays an important role in targeting mature histone mRNA from the nucleus to the cytoplasm and to the translation machinery (PubMed:8957003, PubMed:9049306, PubMed:12588979, PubMed:19155325).
Stabilizes mature histone mRNA and could be involved in cell-cycle regulation of histone gene expression (PubMed:8957003, PubMed:9049306, PubMed:12588979, PubMed:19155325).
Involved in the mechanism by which growing oocytes accumulate histone proteins that support early embryogenesis (By similarity).
Binds to the 5' side of the stem-loop structure of histone pre-mRNAs (By similarity).

Biological Process

Biological Process cap-dependent translational initiationManual Assertion Based On ExperimentIDA:ComplexPortal
Biological Process mRNA 3'-end processing by stem-loop binding and cleavageISS:UniProtKB
Biological Process mRNA transportManual Assertion Based On ExperimentIDA:UniProtKB

Cellular Location

Cytoplasm
Nucleus
Polyribosome-associated (PubMed:12588979).
Localizes predominantly in the nucleus at the G1/G2 phases and the beginning of S phase (PubMed:12588979).
Through the S phase, partially redistributes to the cytoplasm (PubMed:12588979).
Binding to histone mRNA is necessary for cytoplasmic localization (PubMed:12588979).
Shuttles between the nucleus and the cytoplasm (PubMed:15829567).
Imported in the nucleus by the Importin alpha/Importin beta receptor (PubMed:15829567).

PTM

Phosphorylated on Thr-61 and Thr-62 in the S-phase. Phosphorylation of Thr-62 by CDK1 primes phosphorylation of Thr-61 by CK2. Phosphorylation of Thr-62 is required for its degradation by the proteasome at the end of the S phase. Its degradation is not required for histone mRNA degradation at the end of the S phase. All the phosphorylated forms detected are present in the cytoplasm. Both unphosphorylated and phosphorylated forms bind the stem-loop structure of histone mRNAs. Phosphorylation at Thr-171 increases affinity for histone mRNAs.
Ubiquitinated by the CRL2(FEM1A), CRL2(FEM1B) and CRL2(FEM1C) complexes, leading to its degradation.