At present, only little is known about the enzymatic machinery required for 𝑁-glycosylation in Chlamydomonas reinhardtii , leading to the formation of 𝑁-glycans harboring Xyl and methylated Man. This machinery possesses new enzymatic features, as C. reinhardtii N -glycans are independent of 𝛽1,2-𝑁-acetylglucosaminyltransferase I. Here we have performed comparative 𝑁-glycoproteomic analyses of insertional mutants of mannosidase 1A (IM Man1A ) and xylosyltransferase 1A (IM XylT1A ). The disruption of man1A affected methylation of Man and the addition of terminal Xyl. The absence of XylT1A led to shorter 𝑁-glycans compared to the wild type. The use of a IM Man1A xIM XylT1A double mutant revealed that the absence of Man1A suppressed the IM XylT1A phenotype, indicating that the increased 𝑁-glycan trimming is regulated by core 𝛽1,2-Xyl and is dependent on Man1A activity. These data point toward an enzymatic cascade in the 𝑁-glycosylation pathway of C. reinhardtii with interlinked roles of Man1A and XylT1A. The results described herein represent the first step toward a functional characterization of the enzymatic 𝑁-glycosylation machinery in C. reinhardtii .