A single exon of 4277 bases.

KLLN shares a transcription start site with PTEN and is transcribed from the minus strand.

None.

Calculated molecular weight: 19827 Da.

178 amino acids, DNA binding domain amino acids 8-50.

Nucleus.

KLLN, a target gene of the tumor suppressor p53, is involved in cell cycle arrest and apoptosis (Cho and Liang, 2008). In breast cancer cell lines, KLLN overexpression inhibits cellular proliferation and leads to cell cycle arrest and apoptosis while KLLN knockdown increases cellular proliferation (Wang et al., 2013b). KLLN can bind to DNA and act as a transcription factor; regulating the expression of genes including TP53, TP73, AR and CHK1 (Nizialek et al., 2013 ; Wang et al., 2013b).

None.

37% of Cowden syndrome patients who were PTEN mutation negative had KLLN promoter hypermethylation which was not seen in controls. Patients with KLLN promoter hypermethylation have an increased risk of breast and renal cancer compared to PTEN mutation positive patients. Methylation leads to a 250-fold decrease in KLLN expression (Bennett et al., 2010).
Germline KLLN promoter methylation has been observed in 56% of patients with apparently sporadic renal cell carcinoma (Bennett et al., 2011).
Germline KLLN mutations have been associated with apparently sporadic breast cancer. 3% of patients with sporadic breast cancer were found to have KLLN mutations while no mutations were observed in controls. Patients with KLLN mutations had a significant family history of breast cancer. These variants were found to dysregulate G2 cell cycle arrest possibly through dysregulated CHK1 expression (Nizialek et al., 2013).

Somatic KLLN promoter hypermethylation is seen in renal cell carcinoma (Bennett et al., 2011).
Somatic KLLN deletions were observed in 20% of breast carcinomas (Nizialek et al., 2013).