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Protein HNRPA1 PDB 1ha1.png
Available structures
PDB Human UniProt search: PDBe RCSB
Aliases HNRNPA1, ALS19, ALS20, HNRPA1, HNRPA1L3, IBMPFD3, hnRNP A1, hnRNP-A1, UP 1, heterogeneous nuclear ribonucleoprotein A1
External IDs HomoloGene: 134664 GeneCards: HNRNPA1
Species Human Mouse
RefSeq (mRNA)



RefSeq (protein)



Location (UCSC) Chr 12: 54.28 – 54.29 Mb n/a
PubMed search [1] n/a
View/Edit Human

Heterogeneous nuclear ribonucleoprotein A1 is a protein that in humans is encoded by the HNRNPA1 gene.[2] Mutations in HNRNPA1 are causative of the syndrome multisystem proteinopathy.


This gene belongs to the A/B subfamily of ubiquitously expressed heterogeneous nuclear ribonucleoproteins (hnRNPs). The hnRNPs are RNA binding proteins and they complex with heterogeneous nuclear RNA (hnRNA). These proteins are associated with pre-mRNAs in the nucleus and appear to influence pre-mRNA processing and other aspects of mRNA metabolism and transport. While all of the hnRNPs are present in the nucleus, some seem to shuttle between the nucleus and the cytoplasm. The hnRNP proteins have distinct nucleic acid binding properties. The protein encoded by this gene has two repeats of quasi-RRM domains that bind to RNAs. It is one of the most abundant core proteins of hnRNP complexes and it is localized to the nucleoplasm. This protein, along with other hnRNP proteins, is exported from the nucleus, probably bound to mRNA, and is immediately re-imported. Its M9 domain acts as both a nuclear localization and nuclear export signal. The encoded protein is involved in the packaging of pre-mRNA into hnRNP particles, transport of poly A+ mRNA from the nucleus to the cytoplasm, and may modulate splice site selection. Multiple alternatively spliced transcript variants have been found for this gene but only two transcripts are fully described. These variants have multiple alternative transcription initiation sites and multiple polyA sites.[3]


Heterogeneous nuclear ribonucleoprotein A1 has been shown to interact with BAT2,[4] Flap structure-specific endonuclease 1[5] and IκBα.[6]

Role in disease[edit]

Mutations in hnRNP A1 are a cause of amyotrophic lateral sclerosis and multisystem proteinopathy.


  1. ^ "Human PubMed Reference:". 
  2. ^ Saccone S, Biamonti G, Maugeri S, Bassi MT, Bunone G, Riva S, Della Valle G (Mar 1992). "Assignment of the human heterogeneous nuclear ribonucleoprotein A1 gene (HNRPA1) to chromosome 12q13.1 by cDNA competitive in situ hybridization". Genomics. 12 (1): 171–4. doi:10.1016/0888-7543(92)90424-Q. PMID 1733858. 
  3. ^ "Entrez Gene: HNRPA1 heterogeneous nuclear ribonucleoprotein A1". 
  4. ^ Lehner B, Semple JI, Brown SE, Counsell D, Campbell RD, Sanderson CM (Jan 2004). "Analysis of a high-throughput yeast two-hybrid system and its use to predict the function of intracellular proteins encoded within the human MHC class III region". Genomics. 83 (1): 153–67. doi:10.1016/S0888-7543(03)00235-0. PMID 14667819. 
  5. ^ Chai Q, Zheng L, Zhou M, Turchi JJ, Shen B (Dec 2003). "Interaction and stimulation of human FEN-1 nuclease activities by heterogeneous nuclear ribonucleoprotein A1 in alpha-segment processing during Okazaki fragment maturation". Biochemistry. 42 (51): 15045–52. doi:10.1021/bi035364t. PMID 14690413. 
  6. ^ Hay DC, Kemp GD, Dargemont C, Hay RT (May 2001). "Interaction between hnRNPA1 and IkappaBalpha is required for maximal activation of NF-kappaB-dependent transcription". Mol. Cell. Biol. 21 (10): 3482–90. doi:10.1128/MCB.21.10.3482-3490.2001. PMC 100270Freely accessible. PMID 11313474. 

Further reading[edit]