sterile alpha motif domain-containing 4A; protein smaug homolog 1; smaug 1; hsmaug1; SAM domain-containing protein 4A (SAMD4A, KIAA1053, SAMD4, SMAUG1)

Function

• acts as a translational repressor of SRE-containing messengers
• when expressed in fibroblasts, hSmaug 1 forms cytoplasmic granules that contain polyadenylated mRNA & the RNA-binding proteins Staufen, TIAR, TIA-1, & HuR
• Smaug1 foci are distinct from degradation foci
• role in RNA granule formation
• role in translation regulation at post-synaptic densities

Structure

• belongs to the SMAUG family
• contains 1 SAM (sterile alpha motif) domain

Compartment

• cytoplasm. cell projection, dendrite
• cell junction, synapse, synaptosome (putative)
• enriched in synaptoneurosomes (putative)
• shuttles between the nucleus & the cytoplasm (CRM1-dependent)
• colocalizes throughout the cytoplasm in granules with polyadenylated RNAs, PABPC1 & STAU1
• also frequently colocalizes in cytoplasmic stress granule-like foci with ELAVL1, TIA1 & TIAL1
• murine protein is abundant in post-synaptic densities
• present in synaptoneurosomal 20 S particles (putative)

Alternative splicing

named isoforms=3

Expression

• murine protein mSmaug 1 is expressed in CN

More general terms

• sterile alpha motif domain-containing protein (SAMD)

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=23034
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:23034
• OMIM: https://mirror.omim.org/entry/610747
• UniProt: http://www.uniprot.org/uniprot/Q9UPU9.html