alpha-actinin-4; non-muscle alpha-actinin 4; F-actin cross-linking protein (ACTN4)

Function

• F-actin cross-linking protein which is thought to anchor actin to a variety of intracellular structures
• ACTN4 is a bundling protein
• binds TRIM3 at the N-terminus (putative)
• interacts with BAIAP1 & PDLIM2

Structure

• homodimer; antiparallel (putative)
• belongs to the alpha-actinin family
• contains 1 actin-binding domain
• contains 2 CH (calponin-homology) domains
• contains 2 EF-hand domains
• contains 4 spectrin repeats

Compartment

• nucleus, cytoplasm
• colocalizes with actin stress fibers
• nuclear translocation can be induced by the PI3 kinase inhibitor wortmannin or by cytochalasin D

Expression

widely expressed

Pathology

• exclusively localized in the nucleus in a limited number of cancer cell lines
  • breast cancer cell line MCF7
  • oral floor cancer IMC2
  • bladder cancer KU7
• cytoplasmic localization of ACTN4 may be associated with cancer metastases due to enhanced cell motility
• defects in ACTN4 are the cause of familial focal segmental glomerulosclerosis 1

More general terms

• alpha-actinin (ACTN)
• nuclear protein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=81
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:81
• OMIM: https://mirror.omim.org/entry/603278
• OMIM: https://mirror.omim.org/entry/604638
• UniProt: http://www.uniprot.org/uniprot/O43707.html