The periplasmic carbonic anhydrase, CAH1, is absent in the sequenced chlamydomonas reinhardtii strain, CC-503

Bratati Mukherjee, Louisiana State University
Trang T. Pham, Louisiana State University
Yunbing Ma, Louisiana State University
Tiffany A. Simms, Louisiana State University
James V. Moroney, Louisiana State University

Abstract

© Zhejiang University Press, Hangzhou and Springer-Verlag Berlin Heidelberg 2013. The Chlamydomonas reinhardtii strain CC-503 (cw-92, mt+), is a cell wall deficient strain that was used in the C. reinhardtii genome sequencing project. During the course of working with this strain, it was discovered that it lacks the periplasmic carbonic anhydrase, CAH1. The protein is undetectable on immunoblots probed with a polyclonal CAH1 antibody although other Carbon Concentrating Mechanism (CCM) proteins are found to be present in the expected amounts. However, the amount of CAH1 mRNA in CC-503, analyzed by quantitative RT-PCR (qRT-PCR), shows no significant difference when compared to other wild-type strains, both walled and cell wall deficient. CC-503 shows reduced growth at lower pH conditions but no significant deficiency in the induction of the CCM. By serving as a natural CAH1 mutant, this strain could be used in experiments investigating the importance of this carbonic anhydrase in C. reinhardtii.