We study Amt and Rh proteins, which appear to be membrane channels for hydrated gases. They are the only two members of their superfamily. The Amt proteins are channels for ammonium. The Rh proteins, of Rh blood group substance fame, appear to be channels for carbon dioxide (probably H2CO3). We focus on the physiological roles of Rh and Amt proteins in the green alga Chlamydomonas reinhardtii. We continue collaborations to determine the structures of bacterial enhancer-binding proteins, which regulate transcription by the sigma54 holoenzyme form of RNA polymerase.
Watson M. Laetsch
Dr. Laetch grows walnuts commercially, raises antique apple varieties, and has a vineyard producing Chardonnay and Merlot grapes, from which he makes wine. He serves on the CNR Advisory Board, is Co-Chair of Bancroft Library Capital Campaign, and Mark Twain Lunch Club; as a Board Member, Friends of Cal History, and leads Bear Treks with his wife. He's the past & present Chair, Board of Directors, Children's Hospital Oakland Research Institute; Member, Board of Directors, Children's Hospital and Research Center at Oakland, and Member, Board of Trustees, University of California Press Foundation.
Most of the proteins involved in photosynthetic energy conversion and electron transport seem organized into integral membrane protein complexes. I study the structure-function relationships of the cytochrome b6f complex, an essential electron transfer complex that links the two photosystems in all oxygenic photosynthetic organisms.
We researched the molecular mechanism of auxin action, using auxin-inducible genes as probes. We isolated novel, interacting proteins that bind to the auxin responsive domains, and constructed Arabidopsis transgenic lines for isolating mutants responsible for transcriptional activation by auxin. We also researched ACC synthase gene expression regulation. We used some ACS genes as molecular probes to study signal transduction pathways responsible for auxin inducibility of ACC synthase gene expression.
|After 27 years studying baculovirus pathogenesis, Dr. Volkman retired from Cal in January, 2007. Her work showed that baculoviruses uniquely usurp the actin cytoskeleton for progeny production. In 2006, her lab and that of Dr. Matthew Welch demonstrated that the interaction of viral protein Ac p78/83 and the cellular Arp2/3 complex regulates nuclear actin in baculovirus-infected cells (Science 314,464-468, 06). Dr. Volkman continues to participate in baculovirus research as a Welch lab guest member at U.C., Berkeley, and as an Expression Systems advisory board member in Woodland, CA.|