Figure 4.
β4a-A protein–protein interactions. A, Yeast two-hybrid screening of a human cerebellar cDNA library identified Syt I and MAP1A as proteins that interact with the β4a-A. The green highlighted areas correspond to the protein regions encoded by the cDNAs isolated in the primary yeast two-hybrid screens. The Syt I cDNA codes for amino acids 95–337 of the full-length Syt I protein; the MAP1A cDNA codes for amino acids 2508–2775, corresponding to the complete LC2 domain of MAP1A. B, Characterization of β4a-A, β4b-A, and β3-A interactions with Syt I and MAP1A. Bait–target pairs were tested under two conditions: column 1, plates lacking leucine and tryptophan (DDO plates); column 2, plates lacking leucine, tryptophan, adenine, and histidine and supplemented with 30 mm 3′-AT. Growth of yeast colonies as shown in column 2 are indicative of interactions of β4a-A and β3-A with Syt I (rows 4 and 6, respectively) and interaction of β4a-A with MAP1A (row 7).