All expression constructs were created with Gateway Technology (Life Technologies) according to the manufacturer’s instructions. These constructs encoded 3×HA-POC1B wild-type and variants (p.Arg106Pro and p.Gln67del) and 3×FLAG-FAM161A for coimmunoprecipitation and encoded monomeric red fluorescent protein (mRFP)-POC1B wild-type and variants and PalmMyr-CFP-FAM161A for colocalization studies. cDNA constructs encoding the full-length POC1B of 478 amino acids (POC1B; RefSeq accession numbers NM_172240.2 [gene] and NP_758440.1 [protein]) or different fragments thereof were generated by Gateway-adapted PCR and subsequently cloned.20 The first fragment (POC1B-WD40) spanned amino acids 1–297 and contained the WD40 domain. The second fragment (POC1B-SR) spanned amino acids 298–426 and did not hold any known domains. The third fragment (POC1B-CC) spanned amino acids 427–478 and contained a single coiled-coil domain (Figure S1). Constructs encoding POC1B variants p.Gln67del and p.Arg106Pro were generated by site-directed mutagenesis PCR. Constructs encoding the full-length FAM161A were generated from a full-length FAM161A clone.21 The sequence of all entry clones was verified by Sanger sequencing.