Submission Date


Document Type

Paper- Restricted to Campus Access


Biochemistry & Molecular Biology


Rebecca Lyczak

Committee Member

Samantha Wilner

Committee Member

Stephen C. Kolwicz Jr.

Department Chair

Eric Williamsen

Department Chair

Anthony Lobo

Project Description

Puromycin-sensitive aminopeptidases (PSAs) are M1 family metalloproteases that regulate the cell cycle, fertility, and embryogenesis in many organisms. The PSA homolog found in the nematode Caenorhabditis elegans is known as PAM-1, and it cleaves the N-terminus of unknown target proteins. The PAM-1 protein is required for embryogenesis, cell cycle progression and polarization of the anteroposterior (AP) body axis. Suppressor mutations in C. elegans pam-1 mutants have been shown to significantly improve embryonic survival and restore polarity phenotypes. One novel suppressor of pam-1, spam-3(lz6), is of further interest because it has been shown to increase embryonic viability from 7.1% in pam-1(or347) mutant worms to 78.53% in pam-1(or347) mutants with the lz6 suppressor. In this study, pam-1 mutants demonstrate defects in early embryo polarity phenotypes necessary for AP axis formation that are significantly rescued in the presence of the lz6 suppressor mutation. This study further explores the mechanisms by which lz6 restores polarity by comparing the functional role and expression levels of non-muscle myosin II (NMY-II), a protein necessary for the maintaining the asymmetry in the C. elegans one-cell embryo, in pam-1 mutants and pam-1 mutants homozygous for the lz6 suppressor.