suppressin; deformed epidermal autoregulatory factor 1 homolog; nuclear DEAF-1-related transcriptional regulator; NUDR; zinc finger MYND domain-containing protein 5 (DEAF1, SPN, ZMYND5)

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Function

when secreted, inhibits of cell cycle in G0/G1
- lymphocytes
- colonic cells
binds to DNA with multiple copies of TTC[CG]G
- present in its own promoter
- present in HNRPA2B1 gene
- own-regulates transcription of these genes
binds to the retinoic acid response element (RARE) (AGGGTTCACCGAAAGTTCA)
activates the proenkephalin gene independently of promoter binding

isoform 1: nucleus, cytoplasm
- cytoplasmic in non-mucinous colorectal carcinoma
- when expressed alone, localized almost exclusively in the nucleus but, when expressed with isoform 4, nuclear expression decreases to 32% & cytoplasmic expression increases by 270%
isoform 2: secreted in some cell types
isoform 3: secreted in some cell types
isoform 4: cytoplasm, nucleus
- when expressed alone, localizes mainly in the cytoplasm but, when expressed with isoform 1, nuclear localization is enhanced

expressed in various tissues & cells including peripheral blood mononuclear cells & hormone-secreting pituitary cells

nuclear localization of suppressin in colorectal carcinomas protends poor prognosis
defects in DEAF1 could confer a growth advantage to the mutated cell; implications for neoplasia
expression in pancreatic lymph nodes of patients with type 1 diabetes is 20 times higher than in healthy controls

first described as suppressin (characterized in bovine neuroendocrine & immune cells); however, it is uncertain whether there is another protein suppressin
DEAF1 has been described as a nuclear dimeric protein & suppressin as a secreted monomeric protein