Identification of Suppressor of Clathrin Deficiency-1 ( SCD1 ) and Its Connection to Clathrin-Mediated Endocytosis in  Saccharomyces cerevisiae .
Clathrin is a major coat protein involved in vesicle formation during endocytosis and transport in the endosomal/trans Golgi system. Clathrin is required for normal growth of yeast  (Saccharomyces cerevisiae)  and in some genetic backgrounds deletion of the clathrin heavy chain gene ( CHC1 ) is lethal. Our lab defined a locus referred to as "   s   uppressor of   c   lathrin   d   eficiency" ( SCD1 ). In the presence of the  scd1-v  allele ("v" - viable), yeast cells lacking clathrin heavy chain survive but grow slowly, are morphologically abnormal and have many membrane trafficking defects. In the presence of  scd1-i  ("i"- inviable),  chc1∆  causes lethality. As a strategy to identify  SCD1 , we used pooled linkage analysis and whole genome sequencing. Here, we report that  PAL2  ( YHR097C ) is the  SCD1  locus.  pal2∆  is synthetic lethal with  chc1∆ ; whereas a deletion of its paralog,  PAL1 , is not synthetic lethal with clathrin deficiency. Like Pal1, Pal2 has two NPF motifs that are potential binding sites for EH domain proteins such as the early endocytic factor Ede1, and Pal2 associates with Ede1 Also, GFP-tagged Pal2p localizes to cortical patches containing other immobile phase endocytic coat factors. Overall, our data show that  PAL2  is the  SCD1  locus and the Pal2 protein has characteristics of an early factor involved in clathrin-mediated endocytosis.
Moorthy BT, Sharma A, Boettner DR, Wilson TE, Lemmon SK