Plasma membrane calcium ATPase expression in human lens epithelium cell lines

To study the expression of four plasma membrane calcium ATPase (PMCA) isoforms in human lens epithelium cell lines (HLE-B3 cells) both on mRNA and protein levels.

Both total mRNA and membrane protein samples were collected, after HLE B3 cells were cultured to 90% confluent. Reverse Transcription Polymerase Chain Reaction (RT-PCR) were used to detect mRNAs of PMCA isoform1, 2, 3 and 4 by using corresponding PMCA isoform 1, 2, 3 and 4 primers. Western Blot analysis was employed to detect PMCA isoform 1, 2, 3 and 4 protein using corresponding anti-PMCA1, 2, 3 and 4 antibodies.

A 420 bp fragment was amplified with PMCA 1 primer. A 550 bp fragment was amplified with PMCA 2 primer. A 840 bp fragment was amplified with PMCA 4 primer. No fragment was amplified with PMCA 3 primer. Western Blotting confirmed that the expected ~153 kDa, ~125 kDa and ~147 kDa protein were recognized by anti PMCA1, 2 and 4 antibodies respectively. No protein was recognized by PMCA 3 antibody.

This is the first study showing only PMCA 1, 2 and 4 gene are expressed in HLE-B3 cells on both mRNA and protein level. PMCA 3 is not expressed in HLE B3 cells. The PMCA isoforms expression pattern in HLE B-3 cell lines is different from that in the lens of other species. PMCA2 may play a more important role over other isoforms.