Submission Date


Document Type

Paper- Restricted to Campus Access




Rebecca Lyczak

Committee Member

Jennifer Gabel

Committee Member

Meghan Tierney

Department Chair

Dale Cameron

Project Description

The puromycin-sensitive aminopeptidase, PAM-1, is needed for meiotic exit and anteroposterior axis formation in early Caenorhabditis elegans embryos. PAM-1 is also involved in oocyte maturation and the oocyte-to-embryo transition. How PAM-1 regulates these activities remains unknown. In this study, two proteins, MBK-2 and CDK-1, are studied to investigate their relationship with PAM-1. MBK-2 is a protein kinase that regulates the degradation of MEI-1, a katanin-related protein, during meiotic exit, and transduces polarity signals that control asymmetric division. In oocytes and early embryos of wildtype C. elegans, MBK-2 is found along the perimeter of the late-stage oocytes. After activation, it breaks down and speckles throughout the embryos, with the amount of speckling decreasing before the first mitosis. CDK-1 is a cyclin-dependent kinase that has feedback loops with two proteins, WEE-1.3, which negatively regulates it, and CDC-25.1 which positively regulates it. This protein is activated in late-stage oocytes to allow them to mature. Since MBK-2 and CDK-1 are both involved in processes that PAM-1 regulates, we hope to uncover how they may work together. Through studying them in wildtype and pam-1 mutant C. elegans, we hope to gain insight into their roles in developmental processes and better understand PAM-1. C. elegans with the appropriate components tagged with GFP were imaged using a Nikon EZ-C3 Confocal Microscope. We saw that MBK-2 breaks down faster in pam-1 C. elegans when compared to wildtype and that MBK-2 breakdown begins immediately after protrusion of the first polar body. cdk-1(RNAi) was seen to affect wildtype and pam-1 C. elegans similarly during oocyte maturation, but additional study is needed to see if there is a potential interaction between PAM-1 and CDK -1. From the results of this study and others, there is a possibility that PAM-1 interacts with MBK-2 and CDK-1 by directly or indirectly activating these proteins or WEE-1.3 and CDC-25.1. We noted that mutant pam-1 leads MBK-2 to break down faster, showing that PAM-1 is likely working upstream of this kinase to lead to its defect.


Funding for this research was provided by the National Institutes of Health grant number 2R15GM110614-03.