Mary Porter

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Credentials

PhD

Research Summary

The Porter lab focuses on identifying the genes and gene products that regulate the ciliary assembly and motility using Chlamydomonas as the experimental model for gene discovery. Given that cilia and flagella are highly conserved structures, more than 80% of the genes identified have obvious vertebrate orthologues, and many have been implicated in human disorders such as infertility, chronic respiratory disease, polycystic kidney disease, and a variety of developmental defects. Current projects in the lab are focused on two major topics: 1) Regulation of motility. We use both classical genetics and insertional mutagenesis to identify novel gene products involved in the regulation of dynein motor activity. Biochemical characterization of the encoded polypeptides indicates that many serve as structural scaffolds that interconnect microtubules and limit dynein-driven sliding. Others mediate that attachment of regulatory enzymes that modify dynein activity. Several of these gene products have recently been linked to chronic respiratory disease and infertility.2) Characterization of motor proteins involved in ciliary assembly. Assembly and maintenance of cilia and flagella requires constant, intraflagellar transport (IFT) of ciliary proteins, similar to the bidirectional transport that occurs in neurons. Our lab identified a novel dynein isoform (Dhc1b/DHC2) that is required for retrograde IFT. We are using genetics, biochemistry, and high-resolution light microscopy to identify and characterize other subunits of the retrograde motor. We are also characterizing mutations in other genes that regulate motor activity.