Spans 9.3kb/ 7.9kb; 10 exons.

2428/ 1029 nucleotides mRNA.

342 amino acids. 44 kDa protein. 5 WD repeats (Hosohata et al., 2003).

p44 is expressed in heart, skeletal muscle, spleen, thymus, prostate, testis, pancreas, and uterus (Hosohata et al., 2003).
In adult prostate, p44 is expressed as nuclear protein in glandular epithelial cells and not in stromal cells (Zhou et al., 2006).
In testis, p44 expression is seen in germ cells and Leydig cells, but not expressed in peritubular myocytes and Sertolis cells (Liang et al., 2006).

p44 has both nuclear and cytolasmic localization patterns (Zhou et al., 2006; Liang et al., 2006; Peng et al., 2008). In benign prostate and testicular cells, p44 is found predominantly in the nucleus. In prostate cancer and malignant testicular cells (seminomas and leydig cell tumor), p44 is found in the cytoplasm. The p44 cytoplasmic translocation may be an indicative marker of cancer in these tissues.

p44 interacts with androgen receptor and acts as a positive coactivator for androgen-dependent AR transactivation (Hosohata, 2003). Nuclear p44 causes an androgen-dependent G1 arrest growth inhibition in prostate cells expressing androgen receptor (Zhou et al., 2006; Peng et al., 2008). Cytoplasmic and nuclear p44 may have opposite functions, as introduction of p44 to the cytoplasm accelerates growth (Peng et al., 2008).
p44 is part of the PRMT5 (protein arginine methyl transferase 5) complex important for methylosome activity (Hosohata et al., 2003; Friesen et al., 2002). p44 interacts with FCP1 phosphatase (Licciardo et al., 2002) and histone H2A (Furuno et al., 2006).

WD repeats commonly seen for multiple protein interactions.

Unknown