Protein Names (UNIPROT)

Piwi-like protein 2

Protein function and interaction

The piwi family genes, which are defined by conserved PAZ and Piwi domains, play important roles in stem cell self-renewal, RNA silencing, and translational regulation in various organisms. In mouse Kuramochi-Miyagawa et al. (2004) (PMID: 14736746) showed that MILI is essential for the differentiation of spermatocytes.

It was shown that Piwil2 modulates expression of stem cell specific genes, including platelet-derived growth factor receptor, beta polypeptide (Pdgfrb), solute carrier family 2 member 1 (Slc2a1), gap junction membrane channel protein alpha 7 (Gja7), the spermatogonial cell surface markers Thy-1 (CD90), integrin alpha 6 (Itga6), CD9, and the spermatogonia specific markers heat shock protein 90 alpha (Hsp90a), and stimulated by retinoic acid gene 8 (Stra8) ( Lee et al., 2006 PMID: 16261612).

Members of the Argonaute family are known to associated with DICER. PIWIL2 may be involved in the development and maintenance of stem cells through the RNA-mediated gene-quelling mechanisms associated with RNA silencing pathway (Sasaki et al., 2003 PMID: 12906857). A new class of small RNAs, refered to as "Piwi-interacting RNAs" or piRNAs, that binds to MILI in mouse male germ cells, is supposed to play an important role in this process (Aravin et al., 2006 PMID: 16751777).

Piwil2 is widely expressed in tumors and acts as an oncogene by inhibition of apoptosis and promotion of proliferation via Stat3/Bcl-X(L) signaling pathway (Lee et al, 2006 PMID: 16377660). It may play an important role during the development of cancer according to the cancer stem cell hypothesis (Gao, 2007 PMID: 18053092).

Lu et al., 2012 (PMID:22303479) have demonstrated that human piwil2 gene suppresses apoptosis by phosphorylating STAT3 along with c-Src and initiating transcriptional silencing of P53. Co-immunoprecipitation assay revealing that the Piwil2 protein was physically associated with STAT3 and c-Src (Lu et al., 2012 PMID:22303479).