Acts as one of several non-catalytic accessory components of the cytoplasmic dynein 1 complex that are thought to be involved in linking dynein to cargos and to adapter proteins that regulate dynein function. Cytoplasmic dynein 1 acts as a motor for the intracellular retrograde motility of vesicles and organelles along microtubules. The intermediate chains mediate the binding of dynein to dynactin via its 150 kDa component (p150-glued) DCTN1. Involved in membrane-transport, such as Golgi apparatus, late endosomes and lysosomes. Homodimer. The cytoplasmic dynein 1 complex consists of two catalytic heavy chains (HCs) and a number of non-catalytic subunits presented by intermediate chains (ICs), light intermediate chains (LICs) and light chains (LCs); the composition seems to vary in respect to the IC, LIC and LC composition. The heavy chain homodimer serves as a scaffold for the probable homodimeric assembly of the respective non-catalytic subunits. The ICs and LICs bind directly to the HC dimer and the LCs assemble on the IC dimer. Interacts with DYNLT3. Interacts with DYNLT1. Interacts (dephosphorylated at Ser-90) with DCTN1 (By similarity). Interacts with BICD2. Interacts with SPEF2 (By similarity). Detected in the cytoplasm of pachytene spermatocytes. Localizes to the manchette in elongating spermatids. The phosphorylation status of Ser-90 appears to be involved in dynactin-dependent target binding. Pyrophosphorylation by 5-diphosphoinositol pentakisphosphate (5-IP7) promotes interaction with DCTN1. Serine pyrophosphorylation is achieved by Mg(2+)-dependent, but enzyme independent transfer of a beta-phosphate from a inositol pyrophosphate to a pre-phosphorylated serine residue. Belongs to the dynein intermediate chain family.