Alternative titles; symbols
HGNC Approved Gene Symbol: CARHSP1
Cytogenetic location: 16p13.2 Genomic coordinates (GRCh38): 16:8,852,942-8,869,006 (from NCBI)
CARHSP1 contains a cold-shock domain with 2 RNA-binding motifs. Proteins containing cold-shock domains bind polypyrimidine regions of single-stranded RNA and DNA and regulate ribosome translation, mRNA degradation, and transcription termination rate. CARHSP1 plays a role in TNF (191160) mRNA stabilization (Pfeiffer et al., 2011).
Using rat Crhsp24 to query an EST database, Groblewski et al. (1998) identified human CARHSP1, which they called CRHSP24. The deduced 147-amino acid human protein has nearly 14% proline content and differs from the rat ortholog at only 5 residues. Northern blot analysis detected Crhsp24 transcripts of approximately 2.9 and 0.7 kb in all rat tissues examined, with highest expression in pancreas, testis, liver, and lung. Western blot analysis of rat tissues revealed an apparent 24-kD protein with a similar expression profile. Immunohistochemical analysis of rat pancreatic acini showed diffuse Crhsp24 staining in cytoplasm, with little or no staining in nuclei or secretory granules.
Pfeiffer et al. (2011) reported that the mouse and human CARHSP1 proteins share about 97% amino acid identity and that both contain a cold-shock domain with 2 RNA-binding motifs. In mouse RAW264.7 macrophages, Carhsp1 localized to cytoplasmic processing bodies containing translationally repressed mRNA. Carhsp1 also appeared to localize to exosomes, which degrade mRNA, but it did not localize with translating mRNA.
Groblewski et al. (1998) found that activation of calcineurin (see 114105) specifically dephosphorylated Crhsp24 in rat pancreatic acinar cells. In basal state, Crhsp24 appeared to be phosphorylated on 4 serines, at least 3 of which were dephosphorylated by calcineurin in response to calcium mobilization. Inhibition of calcineurin prevented calcium-dependent Crhsp24 dephosphorylation.
Schafer et al. (2003) found that phorbol ester and secretin (SCT; 182099) induced calcium-independent Chrsp24 dephosphorylation in rat acinar cells. Inhibitor studies revealed that phorbol ester and secretin induced dephosphorylation of Crhsp24 on at least 2 serines, likely via Pp2a (see 176915) or Pp4 (PPP4C; 602035).
Using an RNA capture assay, Pfeiffer et al. (2011) found that CARHSP1 bound to the 3-prime UTR of TNF mRNA. Overexpression and knockdown studies in RAW264.7 mouse macrophages suggested that mouse Carhsp1 stabilized Tnf in both resting and lipopolysaccharide-stimulated cells.
Hartz (2016) mapped the CARHSP1 gene to chromosome 16p13.2 based on an alignment of the CARHSP1 sequence (GenBank AF115345) with the genomic sequence (GRCh38).
Groblewski, G. E., Yoshida, M., Bragado, M. J., Ernst, S. A., Leykam, J., Williams, J. A. Purification and characterization of a novel physiological substrate for calcineurin in mammalian cells. J. Biol. Chem. 273: 22738-22744, 1998. [PubMed: 9712905] [Full Text: https://doi.org/10.1074/jbc.273.35.22738]
Hartz, P. A. Personal Communication. Baltimore, Md. 3/29/2016.
Pfeiffer, J. R., McAvoy, B. L., Fecteau, R. E., Deleault, K. M., Brooks, S. A. CARHSP1 is required for effective tumor necrosis factor alpha mRNA stabilization and localizes to processing bodies and exosomes. Molec. Cell. Biol. 31: 277-286, 2011. [PubMed: 21078874] [Full Text: https://doi.org/10.1128/MCB.00775-10]
Schafer, C., Steffen, H., Krzykowski, K. J., Goke, B., Groblewski, G. E. CRHSP-24 phosphorylation is regulated by multiple signaling pathways in pancreatic acinar cells. Am. J. Physiol. Gastrointest. Liver Physiol. 285: G726-G734, 2003. [PubMed: 12801884] [Full Text: https://doi.org/10.1152/ajpgi.00111.2003]